nikhilram

2013-04-03T09:03:00.000-07:00

~~Storage interview questions & answers~~

DAS,NAS,SAN?

DAS :

In a Direct Attached Storage (DAS) environment, servers connect directly to the disk array typically via a SCSI interface. The same connectivity port on the Disk array cannot be shared between multiple servers. Clients connect to the Servers through the Local Area Network The distance between the Server and the Disk array is governed by the SCSI limitations. With the

advent of Storage Area Networks and Fibre Channel interface, this method of Disk array access is becoming less prevalent.

NAS:

In a Network Attached Storage (NAS) environment, NAS Devices access the disks in an array via direct connection or through external connectivity. The NAS heads are optimized for file serving. They are setup to export/share file systems. Servers called NAS clients access these file systems over the Local Area Network (LAN) to run applications. The clients connect to these servers also over the LAN.

SAN:

In a Storage Area Network (SAN) environment, servers access the disk array through a dedicated network designated as SAN in the slide. SAN consists of Fibre Channel switches that provide connectivity between the servers and the disk array. In this model, multiple servers can access the same Fibre Channel port on the disk array. The distance between the server and the

disk array can also be greater than that permitted in a direct attached SCSI environment. Clients communicate with the servers over the Local Area Network (LAN).

What is fabric and fabric management?

Ans: A fabric is a virtual space in which all storage nodes communicate with each other over distances. It can be created with a single switch or a group of switches connected together. Each switch contains a unique domain identifier which is used in the address schema of the fabric.

In order to identify the nodes in a fabric, 24-bit fibre channel addressing is used.

Fabric services: When a device logs into a fabric, its information is maintained in a database. The common services found in a fabric are:

􀁹 Login Service

􀁹 Name Service

􀁹 Fabric Controller

􀁹 Management Server

Fabric Management : Monitoring and managing the switches is a daily activity for most SAN administrators. Activities include accessing the specific management software for monitoring purposes and zoning.

What is zoning? What all the different types of zoning?

Ans: There are several configuration layers involved in granting nodes the ability to communicate with each other:

􀁹 Members - Nodes within the SAN which can be included in a zone.

􀁹 Zones - Contains a set of members that can access each other. A port or a node can be members of multiple zones.

􀁹 Zone Sets - A group of zones that can be activated or deactivated as a single entity in either a single unit or a multi-unit fabric. Only one zone set can be active at one time per fabric. Can also be referred to as a Zone Configuration.

In general, zoning can be divided into three categories:

􀁹 WWN zoning - WWN zoning uses the unique identifiers of a node which have been recorded in the switches to either allow or block access A major advantage of WWN zoning is flexibility. The SAN can be re-cabled without having to reconfigure the zone information since the WWN is static to the port.

􀁹 Port zoning - Port zoning uses physical ports to define zones. Access to data is determined by what physical port a node is connected to. Although this method is quite secure, should recabling occur zoning configuration information must be updated.

􀁹 Mixed Zoning – Mixed zoning combines the two methods above. Using mixed zoning allows a specific port to be tied to a node WWN. This is not a typical method.

What is Single HBA Zoning?

Ans: Under single-HBA zoning, each HBA is configured with its own zone. The members of the zone consist of the HBA and one or more storage ports with the volumes that the HBA will use.

Two reasons for Single HBA Zoning include:

􀁹 Cuts down on the reset time for any change made in the state of the fabric.

􀁹 Only the nodes within the same zone will be forced to log back into the fabric after a RSCN (Registered State Change Notification).

What is LUN Masking?

Ans: Device (LUN) Masking ensures that volume access to servers is controlled appropriately. This prevents unauthorized or accidental use in a distributed environment.

A zone set can have multiple host HBAs and a common storage port. LUN Masking prevents multiple hosts from trying to access the same volume presented on the common storage port.

What is iSNS (Internet Storage Name service)?

Ans: Each Fibre Channel Name Service message has an equivalent iSNS message. This mapping is transparent, allowing iFCP fabrics with iSNS support to provide the same services that Fibre Channel fabrics can.

When an iFCP or iSCSI gateway receives a Name Service ELS, it is directly converted to the equivalent iSNS Name Service message. The gateway intercepts the response and maps any addressing information obtained from queries to its internal address translation table before forwarding the Name Service ELS response to the original Fibre Channel requester.

What is Fiber Channel?

Ans: Fibre channel is a set of standards which define protocols for performing high speed serial data transfer. The standards define a layered model similar to the OSI model found in traditional networking technology. Fibre Channel provides a standard data transport frame into which multiple protocol types can be encapsulated. The addressing scheme used in Fibre Channel switched fabrics will support over 16 million devices in a single fabric.

What is Hot Spare?

Ans: A hot spare is an idle component (often a drive) in a RAID array that becomes a temporary replacement for a failed component.

For example:

The hot spare takes the failed drive’s identity in the array.

Data recovery takes place. How this happens is based on the RAID implementation:

􀁹 If parity was used, data will be rebuilt onto the hot spare from the parity and data on the surviving drives.

􀁹 If mirroring was used, data will be rebuilt using the data from the surviving mirrored drive.

The failed drive is replaced with a new drive at some time later.

One of the following occurs:

􀁹 The hot spare replaces the new drive permanently—meaning that it is no longer a hot spare and a new hot spare must be configured on the system.

􀁹 When the new drive is added to the system, data from the hot spare is copied to the new drive. The hot spare returns to its idle state, ready to replace the next failed drive.

Note: The hot spare drive needs to be large enough to accommodate the data from the failed drive

Hot spare replacement can be:

􀁹 Automatic - when a disk’s recoverable error rates exceed a predetermined threshold, the disk subsystem tries to copy data from the failing disk to a spare one. If this task completes before the damaged disk fails, the subsystem switches to the spare and marks the failing disk unusable. (If not it uses parity or the mirrored disk to recover the data, as appropriate).

􀁹 User initiated - the administrator tells the system when to do the rebuild. This gives the administrator control (e.g., rebuild overnight so as not to degrade system performance), however, the system is vulnerable to another

failure because the hot spare is now unavailable. Some systems implement multiple hot spares to improve availability.

What is Hot Swap?

Ans: Like hot spares, hot swaps enable a system to recover quickly in the event of a failure. With a hot swap the user can replace the failed hardware (such as a controller) without having to shut down the system.

Data Availability at the host?

Ans:

Multiple HBAs: Redundancy can be implemented using multiple HBAs. HBAs are the host’s connection to the storage subsystem.

Multi-pathing software: Multi-pathing software is a server-resident, availability enhancing, software solution. It utilizes the available HBAs on the server to provide redundant communication paths between host and storage devices. It provides multiple path I/O capabilities and path failover, and may also provide automatic load balancing. This assures uninterrupted data transfers even in the event of a path failure.

Clustering: Clustering uses redundant host systems connected together. In the event that one of the hosts in the cluster fails, its functions will be assumed by the surviving member(s). Cluster members can be configured to transparently take over each others’ workload, with minimal or no impact to the user.

What is HBA?

Ans: The host connects to storage devices using special hardware called a Host Bus Adapter (HBA).

HBAs are generally implemented as either an add-on card or a chip on the motherboard of the

host. The ports on the HBA are the host’s connection to the storage subsystem. There may be

multiple HBAs in a host.

The HBA has the processing capability to handle some storage commands, thereby reducing the

burden on the host CPU.

What is Volume Manager?

Ans: The Volume Manager is an optional intermediate layer between the filesystem and the physical

disks. It can aggregate several smaller disks to form a larger virtual disk and make this virtual

disk visible to higher level programs and applications. It optimizes access to storage and

simplifies the management of storage resources.

Explain raid levels?

Ans:

RAID 0 – Striped Array with no Fault Tolerance

RAID 1 – Disk Mirroring

RAID 0+1 – Striping and Mirroring

RAID 1+0 – Mirroring and Striping

RAID 3 - Parallel Transfer with Dedicated Parity Disk

RAID 4 - Striping with Dedicated Parity Disk

RAID 5 - Independent Disks with Distributed Parity

What is DWDM?

Ans: Dense Wavelength Division Multiplexing (DWDM)

􀁹 DWDM is a technology that puts data from different sources together on an optical fiber with each signal carried on its own separate light wavelength (commonly referred to as a lambda or λ).

􀁹 Up to 32 protected and 64 unprotected separate

wavelengths of data can be multiplexed into a light

stream transmitted on a single optical fiber.

Explain FCIP, IFCP, ISCSI?

Ans:

• FCIP – TCP/IP based tunneling/encapsulating protocol for connecting/extending Fibre Channel SANs. The entire FC frame is sent over IP links.

• iFCP – Gateway-to-gateway protocol for FCP over IP. Mapping natively in IP across Fibre Channel and IP. An IP-based tunneling protocol for interconnecting Fibre Channel devices together in place of Fibre Channel switches. When iFCP creates the IP packets, it inserts information that is readable by network devices and routable within the IP network. iFCP wraps Fibre Channel data in IP packets but maps IP addresses to individual Fibre Channel ports.

• iSCSI – Native TCP/IP protocol. An IP-based protocol for establishing and managing Connections between IPbased storage devices, hosts, and clients. No Fibre Channel content, but bridging between iSCSI and FC is possible.

What are WWN and WWPN?

Ans:

WWN: All Fibre Channel devices (ports) have 64 bit unique identifiers called World Wide Names (WWN). These WWNs are similar to the MAC address used on a TCP/IP adapter, in that they uniquely identify a device on the network and are burned into the hardware or assigned through software. It is a critical feature, as it used in several configurations used for storage access.

WWPN:However, in order to communicate in the SAN, a port also needs an address. This address is used to transmit data through the SAN from source node to destination node.

What is FC-AL?

Ans: Fibre Channel Arbitrated Loop has a shared bandwidth, distributed topology, and can connect with hubs.

SAN Toplogies?

Ans: SAN Connectivity Topologies

– Point to Point (P-to-P) : Point to Point is a direct connection between two devices.

– Fibre Channel Arbitrated Loop (FC-AL) : Fibre Channel Arbitrated Loop has a shared bandwidth, distributed topology, and can connect with hubs.

– Fibre Channel Switch Fabric (FC-SW): Fibre Channel Switched Fabric (FC-SW) can have multiple devices connected via switching technologies. Fibre Channel Switched Fabric provides the highest performance and connectivity of the three topologies. A switched fabric provides scalability and dedicated bandwidth between any given pair of inter-connected devices. It uses a 24-bit address (called the Fibre Channel Address) to route traffic, and can accommodate as many as 15 million devices in a single fabric.

What is a typical storage area network consists of - if we consider it for implementation in a small business setup ?

If we consider any small buisenss following are essentials componets of SAN

- Fabric Switch
- FC Controllers
- JBOD's

Can you briefly explain each of these Storage area components?

Fabric Swictch: It's a device which interconnects multiple network devices .There are swithes starting from 16 port to 32 ports which connect 16 or 32 machine nodes etc.Vendors who manufacture these kind of switches are Brocade, McData.

FC Controllers : These are Data transfer medias they will sit on PCI slots of Server,u can configure Arrays and volumes on it.

JBOD: Just Bunch of Disks is Storage Box,it consists of Enclosure where set of harddrives are hosted in many combinations such SCSI drives,SAS ,FC,SATA.

What is the most critical component in SAN ?
Each component has its own criticality with respect to buisness needs of a company.

How is a SAN managed ?

There are many management softwares used for managing SAN's to name a few

- Santricity
- IBM Tivoli Storage Manager.
- CA Unicenter.
- Veritas Volumemanger.

Which one is the Default ID for SCSI HBA ?

Generally the default ID for SCSI HBA is 7.
SCSI- Small Computer System Interface
HBA - Host Bus Adaptor

How do you install device drivers for the HBA first time during OS installation ?

In some scenarios you are supposed to install Operating System on the drives connected thru SCSI HBA or SCSI RAID Conrollers,but most of the OS'es will not be updated with drivers for those controllers,that time you need to supply drivers externally,if you are installing windows ,you need to press F6 during the installion of OS and provide the driver disk or CD which came along with HBA.
If you are installing linux you need to type "linux dd" for installing any driver.

What is Array ?

Array is a group of Independent physical disks to configure any Volumes or RAID volumes.

Which are the SAN topologies?

Answer :SAN can be connected in 3 types which are mentioned below:
Point to Point topology
FC Arbitrated Loop ( FC :Fibre Channel )
Switched Fabric

Which are the 4 types of SAN architecture types
Answer :Core-edge
Full-Mesh
Partial-Mesh
Cascade

How many minimum drives are required to create R5 ( RAID 5) ?

Answer : You need to have at least 3 disk drives to create R5.

Can you name some of the states of RAID array ?

Answer : There are states of RAID arrays that represent the status of the RAID arrays which are given below
online
Degraded
Rebuilding
Failed

Name the features of SCSI-3 standard ?

Answer : QAS: Quick arbitration and selection
Domain Validation
CRC: Cyclic redundancy check

Can we assign a hot spare to R0 (RAID 0)array?

Answer :No, since R0 is not redundant array, failure of any disks results in failure of the entire array so we cannot rebuild the hot spare for the R0 array.

Can you name some of the available tape media types ?

Answer :There are many types of tape media available to back up the data some of them are
DLT :digital linear tape - technology for tape backup/archive of networks and servers; DLT technology addresses midrange to high-end tape backup requirements.
LTO :linear tape open; a new standard tape format developed by HP, IBM, and Seagate.
AIT :advanced intelligent tape; a helical scan technology developed by Sony for tape backup/archive of networks and servers, specifically addressing midrange to high-end backup requirements.

what is HA ?

Answer : HA High Availability is a technology to achieve failover with very less latency. Its a practical requirement of data centers these days when customers expect the servers to be running 24 hours on all 7 days around the whole 365 days a year - usually referred as 24x7x365. So to achieve this a redundant infrastructure is created to make sure if one database server or if one app server fails there is a replica Database or Appserver ready to takeover the operations. End customer never experiences any outage when there is a HA network infrastructure.

What is virtualization?

Answer :Virtualization is logical representation of physical devices. It is the technique of managing and presenting storage devices and resources functionally, regardless of their physical layout or location.Virtualization is the pooling of physical storage from multiple network storage devices into what appears to be a single storage device that is managed from a central console. Storage virtualization is commonly used in a storage area network (SAN). The management of storage devices can be tedious and time-consuming. Storage virtualization helps the storage administrator perform the tasks of backup, archiving, and recovery more easily, and in less time, by disguising the actual complexity of the SAN.

Symmetrix VMAX - Possible Questions for Interview

What are the major components of Symmetrix VMAX?

System Bay:
VMAX Engines
Matrix Interface Board Enclosure (MIBE)
Power subsystem components
Standby power supplies (SPS)
Service Processor (server, keyboard/video/mouse, UPS).

VMAX Engine:
Symmetrix VMAX systems provide up to eight VMAX Engines within a system bay on standard configurations and up to four VMAX Engines on extended drive loop configurations. Each VMAX Engine includes:
- Two directors that support front-end, back-end and SRDF connections. Each director has:
- 16, 32,or 64 GB of physical memory
- One System Interface board (SIB) that connects the director and the Matrix Interface Board Enclosure (MIBE)
- Two Back End I/O Modules (2 ports, 4 Gb/s) that connect to storage bay drives.
- Two I/ O Module carriers that provide connectivity between each director and the front-end I/O ports. Front End

I/O Modules support:
- Fibre Channel host connectivity (4 ports, 2, 4, or 8 Gb/s)
- Fibre Channel SRDF connectivity (2 ports, 2, 4, 8 Gb/s)
- FICON host connectivity (2 ports, 2, 4, or 8 Gb/s)
- iSCSI host connectivity (2 ports, 1 Gb/s)
- GigE SRDF connectivity.
- Two Management Modules that provide environmental monitoring
- Two VMAX engine power supplies
- Four cooling fans.

Storage Bay:
Disk array enclosures (DAEs)
Power subsystem: PDPs, PDUs, AC connectors
Standby power supply unit (SPS)
Disk array enclosures (DAEs)

Each disk array enclosure contains:
- Two redundant disk array enclosure power /cooling fans
- Two link control card (LCC) modules
- From 5 to 15 drives per direct-attach enclosure
- From 4 to 15 drives per daisy-chain enclosure.

What are the features of VMAX SE?

Supported Disks: 48 to 360 disks
Single V-Max Engine—two directors
FICON, Fibre Channel, iSCSI, Gigabit Ethernet connectivity
Up to 128 GB global memory

What are features of V-MAX?

96 to 2,400 disks, up to 2 PB—three times more usable capacity
One to eight V-Max Engines (16 directors)
Up to 1 TB (512 GB usable) global mirrored memory
Twice the host ports—Fibre Channel, iSCSI, Gigabit Ethernet, FICON connectivity (up to 128 ports*)
Twice the back-end connections for Flash, Fibre Channel, and SATA drives (up to 128 ports)
Quad-core 2.3 GHz processors to provide more than twice the IOPS
Virtual Matrix architecture connects and shares resources across director pairs, providing massive scalability

Explain about Vaulting in VMAX?

Each director pair (2 – odd / even) on the V-Max system will require 200GB of vault space, that is 40 x 5GB chucks of dedicated vault data space
The vault drives are M1 devices with not Raid or mirroring protection
The vault drive cannot to be used by any host and is reserved for the Symmetrix
Vault drives cannot be configured by Timefinder/Snap, virtual or dynamic sparing
The data space created by the vault drives will be almost equivalent to the size of the cache – memory installed on the machine
flash drives, EFD’s cannot be used for vaulting operations
For permanent sparing, 5 vault drives per loop are essential

What are the management tools for Symmetrix VMAX?

Symmetrix Management Console:
The primary interface for managing Symmetrix arrays.

EMC z/OS Storage Manager (EzSM):
An Interactive System Productivity Facility (ISPF) interface that manages Symmetrix system arrays in mainframe environments.

EMC ControlCenter:
An intuitive, browser-based family of products that provides management of the overall storage environment, including multivender storage reporting, monitoring, configuration, and control.

EMC Solutions Enabler SYMCLI:
A library of commands that are entered from a command line or from a script.

EMC SMI-S Provider:
An SMI-compliant interface for EMC Symmetrix and CLARiiON arrays.

What are the supported disk drive types in VMAX?

Symmetrix VMAX systems support Flash, Fibre Channel, and SATA II drives.

What are the features of Enguinity 5874?

Auto-provisioning Groups:
Simplifies provisioning of configurations with alarge number of hosts by allowing the creation of initiator, port and storage groups. Auto-provisioning Groups is especially helpful in large, virtualized server environments that require the availability of many volumes to many host initiators and many storage ports.

Dynamic configuration changes:
Allows the dynamic configuration of BCV and SRDF device attributes. Decreases impact to hosts during BCV and SRDF set and clear operations.

Concurrent configuration changes:
Provides the ability run scripts concurrently instead of serially.

New Management Integration:
New Management Integration features free up host resources and simplify Symmetrix system management by allowing you to:
Load Symmetrix Management Console on the Service Processor
Attach the Service Processor to your network
Open a browser window from any server in the network
Manage the Symmetrix system from anywhere in your enterprise

SRDF Features:
SRDF Extended Distance Protection (SRDF/EDP), Add and remove dynamic devices to SRDF/A (consistency exempt), Two-mirror SRDF Enginuity Consistency Assist (ECA), SRDF/Star with R22 device protection, 250 SRDF group support ,etc..

Tiered storage optimization:
Fully Automated Storage Tiering (FAST) — Reduces cost for performance, saves energy, and simplifies storage tier management by allowing the dynamic allocation of data across storage tiers, based on user defined policies and on the changing performance requirements of the applications.

Enhanced Virtual LUN technology:
Provides the ability to non disruptively change disk and protection type of a logical volume, and allows the migration of open systems, mainframe, and IBM i volumes to unallocated storage, or to existing volume

Virtual Provisioning:

Simplifies storage management:
Improves capacity utilization by allowing the allocation of more storage to than is physically consumed by a host at onset, and is allocated, as needed, from a shared pool.

Automates pool re balancing:
Allows users to nondisruptively balance workloads and extend thin pool capacity, in small increments if required, while maximizing performance and reducing total cost of ownership.

Maximum number of hypers per physical disk in VMAX (Enguinity 5847)?

512

Can we run the concurrent configuration change sessions on VMX?

Yes, each session holds the different configuration change locks.

How many configuration change sessions we can run concurrently on VMAX?

Up to four concurrent configuration change sessions are allowed to run at the same time, when they are non-conflicting. This means that multiple parallel configuration change sessions can run at the same time as long as the changes do not include any conflicts on Device back-end port, Device front-end port and on Device

What is the FAN-OUT ration of VMAX?

512:1

How many mirror position RAID-5 will occupy in VMAX?

One

How many Initiators can be masked to one FA Port in VMAX?

256

Single FA Port can be a member of multiple Port Groups?

Yes.

Which flag has to be enabled before it is member of port group?

ACLX

A device can be a member of multiple storage groups?

Yes

A single HBA can be a member of multiple Initiator groups?

How many members can have one Initiator group?

What is the maximum meta size in VMAX?

255 member * 240GB hyper = ~60TB

How do you list the reserved devices?

symconfigure -sid "SymID" list -reserved

What are the advantages of Auto-Provisioning Groups?

Eliminates of searching for required storage on arrays
Eliminates the mapping and masking devices which requires separate tasks for each initiator/port combinations.
Eliminates the host interruptions
Eliminates the storage reclamination
Initiators can be dynamically added or removed from initiator groups
Ports can be dynamically added or removed from port groups
Storage can be dynamically added or removed from storage groups

What are the different types of ports can be a member of Initiator group?

Only Fibre and Gig-E ports on front end directors allowed

What are the restrictions of Initiator Group?

Initiator can belongs to only one Initiator Group
Maximum of 32 Initiators contains one initiator group
Initiator groups can be cascaded

What are the steps to replace a faulty HBA?

Findout and Note down the old HBA WWN
symaccess list logins
Swap out the old HBA card with new HBA
Discover the new HBA and note down the WWN
Symaccess discover hba or symaccess list hba
Replace the WWN
symaccess -sid "SymID" replace -wwwn "old_WWN" -new_wwn "new_WWN"
Establish the new alias for the HBA
symaccess discover hba -rename

What are the advantages of Thin Provisioning?

Reduce the amount of allocated but unused physical storage
Avoid over allocation of physical storage to applications
Reduces energy consumption and footprint
Provision independently of physical storage infrastructure
Minimize the challenges of growth and expansion
Simplifies data layout
Saves costs by simplifying procedures to add new storage
Reduces disk contention and enhances performance
Maximize return on investment
Avoides the application interuptions/host downtime.

Can you explain step by step procedure to implement Virtual/Thin Provisioning?

Creating Data Devices:
symconfigure -sid "SymID" -cmd "create dev count=16, config=2-Way-Mir, attribute=datadev, emulation=FBA, size=4602;" commit -v -nop

Creating Thin Pool:
symconfigure -sid "SymID" -cmd "create pool PoolName type=thin;" commit -nop

Adding Data Devices to thin pool:
symconfigure -sid "SymID" -cmd "add dev 10E4:10E5 to pool PoolName type=thin, member_state=ENABLE;" commit -nop

Creating Thin Devices:
symconfigure -sid "SymID" -cmd "create dev count=16, size=4602, emulation=fba, config=TDEV;" commit -nop

Binding Thin devices to Thin Pool:
symconfigure -sid "SymID" -cmd "bind tdev 10F4:10F7 to pool PoolName;" commit -nop

Mapping and Masking TDEVs to host:

What is the status of TDEVs before they bound to thin pool?

Not Ready

How many Thin Pools can we create in a Array?

The number of pools that can be configured in a Symmetrix array is 512.
This is the total number of pools, including Virtual Provisioning thin v pools, SRDF/A Delta Set Extension (DSE) pools, or TimeFinder/Snap pools.

Maximum no. Of data devices in a thin pool?

As many as data devices can be member of a thin pool, however the limit to the number of thin and data devices that can be configured within a Symmetrix system is 64,000.

What are the Thin Pools recommendations when you are adding data devices?

Only data devices may be placed in a thin pool.
The data devices must all have the same emulation.
The data devices must all have the same protection type.
It is recommended that data devices in a pool all reside on drives that have the same rotational speed.
The data devices in the pool should generally be spread across as many DAs and drives of a given speed as possible.
The devices should be evenly spread across the DAs and drives.
The wide striping provided by Virtual Provisioning will spread thin devices evenly across the data devices. The storage administrator must ensure that the data devices are evenly spread across the back end.
It is recommended that all data devices in a pool are of the same size. Using different size devices could result in uneven data distribution.
The data device sizes should be as large as possible to minimize the number of devices required to encompass the desired overall pool capacity.

What are the VMAX Storage Optimization features?

Dynamic Cache Partitioning:
Allows the allocation of portions of cache to specific device groups.

Symmetrix Priority Controls:
Allows the prioritization of read I/O and SRDF/S transfers by host applications.

Symmetrix Optimizer:
Optimizes performance by monitoring access patterns on storage arrays and transparently moving data between storage tiers.

Virtual LUN:
Allows the movement of data between storage tiers.

Fully Automated Storage Tiering (FAST):
provides sophisticated background algorithms that can automate the allocation and relocation of data across storage tiers based on the changing performance of applications.

Storage provisioning with symaccess allows you to create a group of devices, a group of director ports, a group of host initiators, and with one command, associate them in what is called a masking view. Once a masking view exists, devices, ports, and initiators can be easily added or removed from their respective groups.

Can you explain the step by step procedure for creating Auto provisioning Groups?

The steps for creating a masking view are:
Search the environment for Symmetrix devices on each HBA
symaccess discover hba

Create a storage group (one or more devices)
symaccess -sid XXXX create -name StorageGroupName -type storage devs 3250:3350

Create a port group (one or more director/port combinations)
symaccess -sid XXXX create -name PortGroupName -type port -dirport 7E:0,7G:1,8F:0

Create an initiator group (one or more host WWNs or iSCSIs)
symaccess -sid XXXX create -name InitiatorGroupName -type initiator -wwn wwn

Create a masking view containing the storage group, port group, and initiator group.
When a masking view is created, the devices are automatically masked and mapped.
symaccess -sid XXXX create view -name MaskingViewName -sg StorageGroupName -pg PortGroupName -ig InitiatorGroupName

What is purpose FAST (Fully Automated Storage Tiering)?

FAST is Symmetrix software that runs background algorithms continuously analyze the utilization (busy rate) of the Symmetrix array devices.
FAST can move the most-used data to the fastest storage, such as Enterprise Flash Drives, the least-used data to the slowest storage, such as SATA drives, while maintaining the remaining data on Fibre Channel drives, based on user-defined Symmetrix tiers and FAST policies.
The objective of tiered storage is to minimize the cost of storage by putting the right data, on the right Symmetrix tier, at the right time.

How do you configure the symmetrix array for FAST?

By defining symmetrix tiers
By defining FAST Policies
By defining storage groups

Symmetrix DMX - Possible Questions for Interview

Can you explain about DMX Architecture?

The Symmetrix DMX features a high-performance, Direct Matrix Architecture (DMX) supporting up to 128 point-to-point serial connections. Symmetrix DMX technology is distributed across all channel directors, disk directors, and global memory directors in symmetrix DMX systems.

Can you briefly explain about symmetrix series products?

Symmetrix 8000/4 was the first symmetrix to introduce a dual bus arcitecture, providing redundancy in the path to memory.

Symmetrix DMX800 is an incrementally scalable, high-end storage array which features modular disk array enclosures.

Symmetrix Direct Matrix Architecture is storage array technology that employs a matrix of dedicated serial point-to-point connections instead of traditional buses or switches.

Symmetrix DMX2 is a channel director specification for the DMX with faster processors and newer components.

Symmetrix DMX-3 and DMX-4 are the latest technology using redundant global memory and largest capacity.

Can you explain Enginuity release code 5773.79.58?

57 represents the DMX3/4 Hardware
73 represents the microcode family
79 represents the field release level to the microcode
58 represents the field release to the service processor code

52 =Symm4, 55 =Symm5, 56 =DMX/DMX2, 57 =DMX3/4, 58 =VMAX.

How many Cache directors, Front-end directors and Back-end directors we can use in DMX-4?

Cache Directors = 4 Min to 8 Max.
Front-end Directors = up to 12 max.
Back-end Directors = 6 Min to 8 Max.

What are the different types of Front-end directors and the purpose of each one?

ESCON (EA) : for mainframe attachment and SRDF family links
FICON (EF) : provides the industry’s highest performance connectivity Option for the mainframe.
Fibre (FA/DA) : Connectivity option for open systems direct and SAN Attachment, and can be used for SRDF family remote Replication links.
iSCSI (SE) : Provides the industry’s first high-end Iscsi Implementation.
GigE (RE) : for SRDF family replication with compression support.

Explain Rule 17 in DMX?

Possible answers:
Rule of 17 ensured that FAs being used for host connectivity were in different power zones.

The rule of 17 is simply a way to make sure that the paths you connect your host to are not running on the same director, but one physically far away from it.

The original Rule of 17 was put into place to ensure that there was a path on each bus (odd and even).The bus architecture went away in DMX-1 ( Symm6). But we had 2 power zones; one zone for directors 1-8, and another zone for directors 9-16. So the Rule of 17 still had value.

but DIR 3 (odd) and DIR 4 (even) reside on different buses yet in the same power zone, so even if you had your host connected to 3 and 4 ..if that power zone went down ..Your hosts went down.

What are the Management Tools for DMX?

Symcli (Symmetrix Command Line Interface)
SMC (Symmetrix Management Console)
ECC (EMC Control Center)

What are the Enginuity Operational Layes?

Symmetrix Based Application
Host Based Symmetrix Application
Independent Software vendor application
EMC Solutions Enabler API
Symmetrix Enginuity Operating Environment Functions
Symmetrix Hardware

What are the major components of System Bay and Storage Bay in DMX?

System Bay Components:
Either six or eight disk directors and up to 12 channel directors (Combined total = 16).
From four to eight global memory directors.
Up to eight power supplies, each of having a dedicated Battery Back Up(BBU)
1U service processor with KVM (keyboard, video screen and mouse) and dedicated UPS.
Three cooling fan assemblies (each containing 3 fans).

Storage Bay Components:
120 or 240 disk drives per storage bay
Each Drive Enclosure (DE) includes:
Two link control cards (LCC).
Redundant power supplies with BBUs to provide standby power.
The DMX-4 storage bay has 2N power zones with independent power cables, each zone capable of powering the fully configured storage bay.
The storage bay can be populated with various combinations of currently available DMX one-inch low-profile 4 Gb/s Fibre Channel disk drives available in:
73 GB, 146 GB, 300 GB, and 400 GB Fibre Channel drives
73 GB and 146 GB Flash drives
500 GB and 1 TB SATA II disk drives

Can you explain about Read Hit, Read Miss and Fast Write and Delayed Write?

Read Hit: In a read hit operation, the requested data resides in global memory. The channel director transfers the requested data through the channel interface to the host and updates the global memory directory. Since the data is in global memory, there are no mechanical delays due to seek and latency.

Read Miss: In a read miss operation, the requested data is not in global memory and must be retrieved from a disk device. While the channel director creates space in the global memory, the disk director reads the data from the disk device. The disk director stores the data in global memory and updates the directory table. The channel director then reconnects with the host and transfers the data. because the data is not in global memory, the symmetrix system must search for data on the disk and then transfer it to the channel adding seek and latency times to the operation.

Fast Write A fast write occurs when the percentage of modified data in global memory is less than the fast write threshold. On a host write command, the channel director places the incoming blocks directly into global memory. For fast write operations, the channel director stores the data in global memory and sends a “channel end” and “device end” to the host computer. The disk director then asynchronously destages the data from global memory to the disk device.

Delayed Fast Write: A delayed fast write occurs only when the fast write threshold has been exceeded. That is the percentage of global memory containing modified data is higher than the fast write threshold. If this situation occurs, the symmetrix system disconnects the channel directors from the channels. The disk director then de-stages the data to disk. When sufficient global memory space is available. The channel directors reconnect to their channels and process the fast I/O requires as a fast write. The symmectrix system continues to process read operations during delayed fast writes with sufficient global memory present, this type of global memory operation rarely occurs.

How do you calculate number of cylinders for 120 GB LUN?

Maximum device sizes by Enginuity version
Enginuity version:__________:MBs:_______:CYLs:______:GBs
Enginuity 5874:_____________:245760:____:262668:____:240
Enginuity 5773 and earlier:_:61425:_____:65520:_____:59

Since DMX-4 supports maximum of 60GB hyper size, we have to create two hypers and form a Meta devices as 120GB LUN.
To calculate cylinders for 60GB LUN use the below formula
Cylinders = 60GB/15 tracks* 8 sectors* 16 blocks * 512 bytes
Cylinders = 60000000000/15*8*16*512
Cylinders = 60000000000/983040
Cylinders = 61035 cyl

To calculate the number of cylinders (for pre-Symmetrix DMX), use either of the following: blocks ÷ 960 or (size in megabytes) x 2.1333

To calculate the number of cylinders (for Symmetrix DMX and Symmetrix V-Max arrays), use the following: 1 cylinder = 15 tracks; each track is 64 KB, 15 x 64 tracks = .937 MB for each cylinder

What is the maximum hyper size in DMX-4?

Maximum Cylinders = 65520
Maximum Capacity = 59GB or 61425 MB

How many hypers can create in a Single disk in DMX4?

255 hypers per disk.

How many members can contain in one Meta?

1 Meta head + 255 members

How many LUN IDs available per FA port?

256 LUN IDs are available per FA port, 255 LUN IDs are usable out of 256.

What is Dynamic LUN addressing?

This feature will automatically selects and assigns the LUN IDs to the devices while device mapping to the port Instead of manually assigning address to the device while mapping

How do you add a new member to the existing Meta?

add dev XXXX to meta XXXX, protect_data=TRUE, bcv_meta_head=XXXX;

or for multiple ranges:
add dev XXX1:XXX6 to meta XXXX, protect_data=TRUE, bcv_meta_head=XXXX;

What is stripping and what is Concatenating?

Stripped Meta Devices:
Meta device addressing by striping divides each Meta member device into a series of stripes, addressing a stripe from each device before advancing to the next stripe on the first device. When writing to a striped volume, equal size stripes of data from each participating drive are written alternately to each member of the set.

Concatenated Meta Devices:
Concatenated devices are volume sets that are organized with the first byte of data at the beginning of the first device. Addressing continues to the end of the first device before any data on the next device is referenced. When writing to a concatenated device, the first meta device member receives all the data until it is full, and then data is directed to the next member and so on

What are the DMX-4 supported disk types, no. of disks and maximum capacity?

FC drives, iSCSI drives and Flash drives
15 drives per DAE
120 drivers per Cage
240 drives per Storage Bay
2400 drives per array If total of 10 storage bays connected
Maximum storage capacity is 1 PB.

Briefly explain the DMX-4 supported Device types?

Standard Devices: A Symmetrix device configured for normal Symmetrix operation under a desired protection method (such as RAID-1,RAID-S, and SRDF®).

Gatekeeper Devices: SCSI commands executed by SYMAPI are transferred to the Symmetrix array via a Symmetrix device that is designated as a Gatekeeper device. The gatekeeper allows you to retrieve configuration and status information from the Symmetrix array without interfering with normal device I/O operations.

Meta Devices: Allow individual devices to be concatenated to create larger devices.

BCV Devices: Specialized devices used to create a local copy of data contained in a standard Symmetrix device, which can be used for backup, restore, decision support, and application testing.

SRDF Devices (R1, R2 and R21) Devices configured as RDF1 or RDF2 to support SRDF operations.
R1 is source device for SRDF operations
R2 is target device for SRDF operations
R21 is used for multi hop SRDF operations

Virtual Devices: A host-accessible device containing track-level location information (pointers), which indicates where the copy session data is located in the physical storage. Device copies use virtual devices to support TimeFinder/Snap operations. Virtual devices consume minimal physical disk storage, as they store only the address pointers to the data stored on the source device or a pool of save devices.,

Save Devices: Special devices (not mapped to the host) that provide physical storage space for pre-update images or changed tracks during a virtual copy session of TimeFinder/Snap operations.

Device Masking (VCM)Devices: Symmetrix devices that have been masked for visibility to certain hosts. The device masking database (VCMDB) holds device masking records and typically resides on a 24 or 48 cylinder disk device..

DRV Devices: A non-user-addressable Symmetrix device used by the Symmetrix Optimizer to temporarily hold user data while reorganization of the devices is being executed. Typically, it is used by the Optimizer in logical volume swapping operations.

What is Vault drives and Hot Spare?

Vault Drivers: At the time of emergency shutdown of an Array, what ever the data in cache memory will be destaged/saved on temporary drives called vault drives

Hot Spare: At the time of physical drive failure hot spare drives will take place

What is Preview, Prepare and Commit while using Symconfigure command?

The preview argument verifies the syntax and correctness of each individual change defined, and then terminates the session without change execution.

The prepare argument performs the preview checks and also verifies the appropriateness of the resulting configuration definition against the current state of the Symmetrix array; the argument then terminates the session without change execution

The commit argument completes all stages and executes the changes in the specified Symmetrix array

What are the possible device service states and device status states?

Device Service States : Normal, Failed and Degraded
Device Status States : Ready, Not Ready and Write Disable.

How do you reserve the devices?

symconfigure -sid XXXX -f createdev.cmd -expire expiration date-owner myself -comment "this devices are reserved for SRDF activity" reserve

How do you create the Disk Groups

We can not create Disk Groups, It should be done by changing BIN file by CE.
We can rename the existing disk groups.
Example: symconfigure -sid 207 -cmd “set disk_group 4 disk_group_name = flash_dsks;” -v -nop commit

How do you check the free space by Disk group and Array as whole?

By Disk Group : Symdisk -sid XXXX list -by_diskgroup
Array as whole : Symconfigure -sid XXXX list -freespace

How do you check the total assigned devices to a particular Host?

Symmaskdb -sid XXXX list devs -wwn "host hba wwn"

How do you check the total allocated storage of a particular Host?

symmaskdb -sid XXXX list capacity -Host hostname

What is pre check list to assign storage to the host?

Verify the available free space in the symmetrix array
symconfigure -sid SymmID [-v | -freespace [-units cylinders | MB]] list
symdisk -sid "SymID" list -disk_group "GroupNumber"

Verify the Symmetrix status
Symconfigure -sid "SymID" verify

If any hung activities found abort
symconfigure -sid "SymID" abort

Explain step by step procedure to provide storage to the Host?

1. Creating STD device
2. Meta Device Creation
3. Mapping
4. Masking

Example:
Create a commandfile with the following entry to create hypers.
Create dev count=8, size=12394, emulation=FBA, config=2-way-mir, disk_group=2;

Execute the command file using symconfigure command with preview, prepare and commit options.
Symconfigure -sid "SymID" -f Commandfile.cmd -v -noprompt commit

Verify the newly created devices
symdev -sid "SymID" list -noport

Create a commandfile with following entry to form metas and devices to the meta head.
Form meta from dev 26CA, config=striped, stripe_size=1920;
add dev 26CB:26E4 to meta 26ca;

Execute the command file using symconfigure command with preview, prepare and commit options.
symconfigure -sid "SymID" -f Commandfile.txt -v -noprompt commit

Verify the newly created meta devices
symdev -sid "SymID" list -noport

Find the host connected Director and Port details
symcfg -sid 4282 list -connections

Find the available addresses on that port
symcfg -sid "SymID" list -address -available -dir 7d -p 0

Create a commandfile with the following entry to map the device to the FA port
map dev 26ca to dir 7d:0, lun=036;

Execute the commandfile using symconfigure with the preview, prepare and commit options.
Symconfigure -sid 4282 -f Commandfile.txt -v -noprompt commit

Mask the devices to the host HBA and refresh the sym configuration
symmaskdb -sid "SymID" -wwn 10000000c93f62cf -dir 7d -p 0 add devs 26ca -nop
Symmask -sid "SymiD" -refresh

Rescan the disks and refresh the powerpath or reboot the server to get the assigned devices at host-end

How do you check particular device geometry?

symdev -sid XXXX show dev 002C

How do you check the particular device is connected to which Host?

symmaskdb -sid XXXX list assignment -dev 002c

What are the steps for storage reclamation?

Unmasking
Write Disable
Un-mapping
Dissolve meta
Deleting hypers

1. Unmasking devices from the host
symmaskdb -sid 4282 -wwn 10000000c93f62cf -dir 7d -p 0 remove devs 26ca

2. Refresh the Symmetrix Array
Symmask -sid 4282 -refresh

3. Write Disable the devices before unmapping from the Director port
symdev -sid 4282 write_disable 26ca -sa 7d -p 0 -noprompt

4. Create a cmd/txt file
Unmap dev 26ca from dir all:all;

5. Perform preview operation using symconfigure command
Symconfigure -sid 4282 -f unmap.txt -v -nop preview

6. Perform prepare operation using symconfigure command
Symconfigure -sid 4282 -f unmap.txt -v -nop prepare

7. Perform Commit operation using symconfigure command
Symconfigure -sid 4282 -f unmap.txt -v -nop commit

8. Verify that the device has been unmapped
Symdev -sid 4282 list -noport

9. To Dissolve meta, create a cmd/txt file
Dissolve meta dev 26ca;

10. Perform preview operation using symconfigure command
Symconfigure -sid 4282 -f dissolve.txt -v -nop preview

11. Perform prepare operation using symconfigure command
Symconfigure -sid 4282 -f dissolve.txt -v -nop prepare

12. Perform Commit operation using symconfigure command
Symconfigure -sid 4282 -f dissolve.txt -v -nop commit

13. Verify that the meta has been Dissoved.
Symdev -sid 4282 list -noport

14. To delete the hypers create a cmd/txt file.
Delete dev 26ca;

15. Perform preview operation using symconfigure command
Symconfigure -sid 4282 -f dissolve.txt -v -nop preview

16. Perform prepare operation using symconfigure command
Symconfigure -sid 4282 -f dissolve.txt -v -nop prepare

17. Perform Commit operation using symconfigure command
Symconfigure -sid 4282 -f dissolve.txt -v -nop commit

18. Verify that Hypers have been deleted.
Symdev -sid 4282 list -noport

How many mirror positions RAID-1 and RAID-5 will occupy?

RAID-1 occupies 2 mirror positions
RAID-5 occupies 2 mirror positions

How do you convert the concatenating meta device to stripped meta?

convert meta XXXX, config=striped, stripe_size=1920, protect_data=TRUE, bcv_meta_head=XXXX;

Host is unable to see the storage, how do you troubleshoot?

Check that the host is logged in to the Array
Check that the cable connectivity status by logging in to the host
Check that the HBA drivers are properly configured
Check the Zoning table by logging in to the switch
Check that the devices status in Array
Check the VCMDB for masking information, etc..

What is Thin Provisioning?

Thin provisioning is a method of optimizing the efficiency with which the available space is utilized in storage area networks. Thin provisioning operates by allocating disk space in a flexible manner among multiple users, based on the minimum space required by each user at any given time.

How do you create thin pools and thin devices?

Creating Thin Pools
Creating Data devs and added these Data devs to Thin Pools
Creating TDEVs and bind these TDEVs to Thin Pool
Assign TDEVs to host.

Explain step by step procedure to setup new host?

Let us assume cable connectivity is done properly
Install HBA drivers in host.
Install Power path if required.
Check that the HBA ports are showing online
Create zoning at switch end.
Check that this host is logged in to the Storage array
Create LUN/hypers in storage array
Form meta devices if required
Map the devices to the FA port.
Mask the devices to the host hba (wwn).
Refresh the Array to affect the changes.

How do you check the failed components in Symmetrix Array?

Symcfg -sid 150 list -env_data -service_state failed

How do you check the failed disks in the Symmetrix Array?

Symdisk -sid XXXX list -failed

What is the purpose of Gate Keeper device?

Low-level I/O commands executed using SYMCLI are routed to the Symmetrix array by a Symmetrix storage device that is specified as a gatekeeper.
The gatekeeper device allows SYMCLI commands to retrieve configuration and status information from the Symmetrix array without interfering with normal Symmetrix operations.
The gatekeeper must be accessible from the host where the commands are being executed.

How many gate keeper devices are required per Array?

It depends on the Symmetrix management applications using in management servers,
As per EMC recommendations 6 gatekeepers are required per management host using symcli

How to list hosts and their EMC registered software, using Solutions Enabler?

Symcfg -sid XXXX list -applications

What is VCMDB and how do you take the backup?

The device masking database (VCMDB) holds device masking records and typically resides on a 24 or 48 cylinder disk device..
Symmaskdb -sid XXXX backup -f filename

How do you list the Hosts which are connected to particular director port?

Symmaskdb -sid XXXX list database -dir XX -p X

How do you check the number of storage bays connected to the system bay and number of disks in each storage bay?

Symcfg -sid XXXX list -env_data

How do check the devices which are not mapped and masked?

Symdev -sid 4282 list dev -noport

How do you check the devices which are mapped to FA but not masked to any host?

Symmaskdb -sid 123 list no_assignment -dir ALL -p ALL

How do you check the login hosts in the Symmetrix Array?

Symmask -sid 4282 list logins

How to display and set the Symmetrix metrics?

Symcfg -sid XXXX -SA all list -v
Set Symmetrix MatricName=MatricValue

How do you check the configured environmental variables?

Symcli -def

Can windows, Linux, Solaris share the same FA in DMX?

Yes, if they share the same port flags

What are the Symmetrix External locks and how to check and release?

Symmetrix external locks are used by SYMAPI (locks 0 to 15) and also for applications assigned by EMC (>15) to lock access to the entire Symmetrix arrayduring critical operations

We can check the external locks by giving the below command
symcfg -sid XXXX list -lockn

We can check the external locks by giving the below command
symcfg release -sid -lockn 15 -force

How to monitor performance of EMC Symmetrix?

Using Performance Monitoring feature in EMC Control Center
Using SYMSTAT symcli command

How do you check the cache activity of front-end directory?

symstat -sid 4282 -type cache -i 5 -c 4 -sa all

How do you check the I/O requests and throughput of selected disk?

Symstat -sid 4282 -type disk -i 5 -c 3 -disk 2a,C,5

What are the available performance types in SYMSTAT command?

REQUESTS: Reports I/O requests and throughput for selected devices, directors, or SRDF/A sessions. (This is the default type; if no type is specified REQUESTS is used.)
BACKEND: Reports back-end I/O requests and throughput for selected devices.
PORT: Reports performance statistics for a director port. ISCSI Report Gig-E network statistics.
CACHE: Reports cache activity for selected front-end or remote link directors, or SRDF/A sessions.
MEMIO: Reports cache memory to disk activity for selected devices. PATH Report R-Copy path information for nonincremental sessions. Symmetrix arrays that have all or some incremental sessions will report an error.
CYCLE: Report cycle summary information for SRDF-A sessions.
DISK: Reports back-end I/O requests and throughput for selected disks.
PREFETCH: Reports track prefetch disk activity for selected back-end directors only.DMSP Reports dynamic mirroring service policy (DMSP) statistics for the selected device(s).
RDF: Reports SRDF statistics from the perspective of RA groups, devices, or directors.

What is symmetrix optimizer and how it works?

Symmetrix Optimizer improves array performance by continuously monitoring access patterns and migrating devices (Symmetrix logical volumes) to achieve balance across the disks in the array
Step 1: Symmetrix Optimizer builds a database of device activity statistics on the Symmetrix back-end.

Step 2: Using the statistical data collected, configuration information, and the user-defined parameters, the Optimizer algorithm identifies busy and idle devicesand their locations on the physical drives. The algorithm tries to minimize average disk service time by balancing I/O activity across physical disks. Optimizer determines which disks require balancing by locating busy devices close to each other on the same disk, and/or by locating busy devices on faster disks or faster areas of the disks. Optimizer takes into account the speed of the disk, the disk geometry, and the actuator speed to determine faster disks.

Step 3: Once a solution for load balancing has been developed, the next phase is to carry out the Symmetrix device swaps. This is done using established TimeFinder technology, which maintains data protection and availability. we can specify whether swaps should occur in a completely automated fashion, or if the device swaps require user approval before the action is taken.

Step 4: Once a swap function completes, Symmetrix Optimizer continues data analysis for the next swap.

What is Symmetrix QoS and how it works?

Quality of Service (QoS) allows more flexibility in managing Symmetrix system’s performance. By increasing the response time for specific copy operations on selected devices, we can increase the overall performance of the other Symmetrix devices.

The QoS (Quality of Service) feature allows us to adjust the data transfer pace on specified devices, or devices in a device group, for certain operations.

The contention for cache access can be quality of service managed by the least recently used (LRU) ring partitions in the Symmetrix cache.

We can control the priority service time of devices and control cache partitions for different device groupings.

What is the purpose of Symmetrix Change Tracker?

To measure changes to data on a Symmetrix volume or group of volumes.
Change Tracker data is often used to analyze and design TimeFinder and Symmetrix Remote Data Facility (SRDF) configurations.
Change Tracker (DeltaMark) session must be created using the symchg create command. The symchg mark command is then used to perform a timestamp and mark the selected area of disk storage occupied by a data object using a DeltaMark bitmap

What is Dynamic Cache Partitioning?

A QoS feature, dynamic cache partitioning allows the Administrator the means to dynamically control the cache area size, servicing a given device group I/O, by defining flexible partitions through cache memory.

Dynamic Cache Partitioning divides the cache memory into multiple partitions with unique names and their device path assignments.

Partition areas can be made static or dynamic in size. The dynamic partitioning provides flexibility to the amount of floating memory that can be allocated with a high and low watermark. This allows memory resources to be temporarily donated to other partitions when needed.

The symqos command allows you to create partitions for different device groupings in addition to the default partition that all devices belong to initially. Each partition will have a target cache percentage as well as a minimum and maximum percentage. In addition, you can donate unused cache to other partitions after a specified donation time.

What are the logs available at host-end and on symmetrix array?

Host-end logs are available in \Symapi\log folder
Event logs and Audit logs in symmetrix array

How do you monitor the real time events on symmetrix array with example?

To monitor real time 100 event records with 600 seconds interval in the symmetrix array
Symevent -sid 4282 monitor -i 600 -c 100 -warn/-error/-fatal

How do you track the history of events on symmetrix array with example?

To list all events in symmetrix array
Symevent -sid 4282 list

To list specific period of time events in event logs
Symevent -sid 4282 list -v -start 9:00 -end 17:00

How do you check the audit logs on symmetrix array?

To show the details about audit log it self.
Symaudit -sid 4282 show

To list the audit log records of specific period of time.
Symaudit -sid 4282 list -v -start_time 7/11:9:00 -end_time 7/11:10:00

To monitor the real time audit logs 100 records with 30sec interval.
symaudit -sid 4282 monitor -i 30 -c 100

What is Symmetrix ACL?

To create access control list on symmetrix array to implement host level or user level security.

Explain step by step to setup the access controls on symmetrix array?

Create Access Group:
(Create a command file with the following entries)
Create accgroup AccessGroupName;
(Execute the command file)
Symacl -sid 4282 commit -file commandfile

Add host access ID or user access ID to access group:
(Create a command file with the following entries)
Add host accid Id name Idname to accgroup GroupName;
Add user accid Id name Idname to accgroup GroupName;
(Execute the command file)
Symacl -sid 4282 -file "CommandFileName" commit

Create Access Pools:
(Create a command file with the following entries)
Create accpool AccessPoolName;
(Execute the command file)
Symacl -sid 4282 commit -file "commandfile"

Add devices to the access pool
(Create a command file with the following entries)
Add dev StartDevName:EndDevName to accpool AccessPoolName;
(Execute the command file)
Symacl -sid 4282 commit -file "commandfile"

Grant Rights to Access Groups:
(Create a command file with the following entries)
Grant access=Base/BCV/RDF to accgroup AccessGroupName to accpool AccessPoolName;
(Execute the command file)
Symacl -sid 4282 commit -file "commandfile"

How do you take the backup/restore of ACLs?

Symacl -sid 4282 backup -file "commandfile"
Symacl -sid 4282 commit -restore -f commandfile

What is Symmetrix User Authorization?

Set up or update the Symmetrix array user authorization information

Explain step by step procedure to setup user authorization on symmetrix array?

User-to-role mappings have to be created:
(Create a command file with the following entry (ex:rolemap.txt))
Assign user H:Host\username to role Monitor;
Assign user D:Eng\username to role Admin;
(Execute the above file)
Symauth -sid 4282 -f rolemap.txt commit.
(Roles: None, Monitor, Storage admin, admin, Auditor, SecurityAdmin)

Enable the user authorization:
Symauth -sid 4282 enable

How do you perform backup and restore user authorization information?

Symauth -sid 4282 backup -f backupfile.cmd commit
Symauth -sid 4282 restore -f backupfile.cmd commit

What is the purpose of bin file in SYMAPI database?

It is a database file in the host which stores the symmetrix array’s configuration data. Can be used to get the configuration data offline.

How do you prepare the Storage Capacity planning reports by host wise?

1. By using EMC Control Center
2. By using symcli commands symcfg and symdisk
Symcfg -sid 4282 list -connections -capacity
Copy and past the output of the above command in excel file and format according to the requirement.
Or
Symdisk -sid 4282 list -by_diskgroup
Copy and past the output of the above command in excel file and do the format according to the requirement.

By using what symcli command we can check the HBA details?

Syminq hba -fibre

SRDF - Possible Questions for Interview

What is Business Continuity?

Business Continuity is the preparation for, response to, and recovery from an application outage that adversely affects business operations.

What are the Business Continuity tools available for symmetrix?

Power path at host end TimeFinder/Mirror, Clone and Snapshot for local replication SRDF for remote replication.

Business Continuity addresses what?

Business Continuity Solutions addresses systems unavailability, degraded application performance, or unacceptable recovery strategies.

What is RPO and RTO?

RPO refers to the maximum amount of data loss an application can tolerate as measured in time. In other words, the amount of data loss that can be tolerated (cost of transaction versus risk).

RTO refers to the maximum time a company budgets to bring an application back online in the event of a disaster. In other words, the time it takes to recover the data once a disaster or other recovery event is declared (risk versus cost)

What are the different types of Device Groups?

Regular, RDF1, RDF2 and Composite group

Briefly explain baout Regular, RDF1 and RDF2 device groups?

Regular device groups are normally used for TimeFinder operations
RDF1 and RDF2 device groups are normally used for SRDF operatins

What is composit group?

A composite group is a user-defined group of device members that can span multiple Symmetrix arrays and SRDF groups. The CG type may be defined as REGULAR,RDF1, RDF2, or RDF21, and may contain various device lists for standard, BCV, virtual (VDEV), RBCV, BRBCV, second hop standard, and second hop BCV.

What is the difference between TimeFinder and SRDF?

Time Finder is for local replication operations
SRDF is for remote replication operations

What are the different types of Remote Link directors used for SRDF?

RF (Fibre Channel directors)
RA (ESCON directors)
MPCD (Multiprotocol Channel Directors) available with these channel connections
FICON
iSCSI for host
GigE (RE) for SRDF

How many dynamic RDF groups can be created in an array?

Symmetrix DMX supports up to 64 total RDF groups.

What are the different types of Link configurations for SRDF?

Unidirectional: If all primary (source or R1) volumes reside in one Array and all secondary (target or R2) volumes reside in another Array, write operations move in one direction, from primary to secondary. Data moves in the same direction over every link in the SRDF group.
Bidirectional: If an SRDF group contains both primary and secondary volumes, write operations move data in both directions over the SRDF links for that group.
Dual-Directional: With a dual-directional configuration, multiple SRDF groups are used; some groups send data in one direction, while other groups send data in the opposite

How the SRDF synchronous mode of operation works?

Write I/O received from host/server at the source
The I/O is transmitted to the target
An acknowledgment is provided by target back to the source
The I/O is serviced to the host

How the SRDF semi synchronous mode of operation works?

An I/O write is received from the host/server at the source.
The I/O is serviced to the host/server.
The I/O is transmitted to the cache of the target.
An acknowledgment is provided by the target back to the source.

How the SRDF Adaptive copy mode of operations works?

Write I/O received from host/server at the source
The I/O is serviced to the host I/O accumulates in/onSymmetrix cache in Write Pending Mode R1 volumes in Disk Mode.
I/O is transmitted to the target.
An acknowledgment is provided by target back to the source.

What is Writing Pending and Disk Mode of Adaptive Copy?

I/O is accumulates in Symmetrix cache in Write Pending Mode
I/O is accumulates in R1 volume in Disk Mode

What is the purpose of Adaptive copy mode?

Adaptive Copy Mode is used primarily for data migrations and data center moves.

How the SRDF Asynchronous mode of operation works?

Write I/O received from host/server at the source
The I/O accumulates in Source Symmetrix cache
The I/O is serviced to the host
The I/O is continually transmitted to the target
The I/O accumulates in Target Symmetrix cache

What is SRDF Domino mode?

Domino Mode is used in conjunction with other SRDF modes except SRDF/A. It effectively stop all write operations to both source and target volumes if target volume become unavailable, or if all SRDF links become unavailable. User will need to manually re-enable the source volumes. While such a shutdown temporarily halts production processing, domino modes can prevent data integrity exposure that causes the inconsistent image on the target volume.

How the SRDF domino mode works?

Write I/O received from host/server at the source
The I/O fails to transmit to the target
Both Source and Target become unavailable

How many R2 devices can be paired with one R1 device concurrently?

Two

What are the restrictions of SRDF device group?

All devices in a disk group must be in the same Symmetrix ICDA
All devices must be of the same type (RDF1, RDF2, Regular)
A device can only belong to a single Device Group per SYMAPI database

How do you check the connectivity status of SRDF link?

Symrdf –sid "SymID" ping
Symrdf –sid "SymID" -RA list all

What are the disaster recovery operations?

Failover: from the source side to the target side, switching data processing to the target side.
Failback: from the target side to the source side by switching data processing to the source side.
Update: the source side after a failover while the target side may still be operational to its local host.

How will failover operation works?

Write Disable device(s) on SA at source (R1)
Suspend RDF link(s)
Read/Write Enable device(s) on RA at target (R2)

How will update operation works?

Suspend RDF link(s)
Merge device track tables between source and target
Resume RDF link(s)

How will failback operation works?

Write Disable device(s) on RA at target (R2)
Suspend RDF link(s)
Merge device track tables between source and target
Resume RDF link(s)
Read/Write Enable device(s) on SA at source (R1)

What are the decision support SRDF operations?

Establish:
Resume Normal SRDF operations
Preserves data on the source (R1) volumes, discarding changes to the target (R2) volumes

Split:
Suspends link between source (R1) and target (R2) volumes
Enables read and write operations on both source and target volumes

Restore
Resume SRDF operations
Preserves data on the target (R2) volumes, discarding changes to the source (R1) volumes

How the split operation will works?

Suspend RDF link(s)
Read/Write Enable device(s) on RA at target (R2) also.

How will establish operation works?

Write Disable device(s) on RA at target (R2)
Suspend RDF link(s)
Resume RDF link(s)
Merge device track tables between source and target
Resume RDF link(s

How will restore operation works?

Write Disable device(s) on SA at source (R1)
Write Disable device(s) on RA at target (R2)
Suspend RDF link(s)
Merge device track tables between source and target
Resume RDF link(s)
Read/Write Enable device(s) on SA at source (R1)

Can you briefly explain about SRDF/S?

SRDF/S is a configuration of multiple Symmetrix units that maintains real time copies of logical volume data in more than one location.
Facility for maintaining real-time or near-real-time physically separate mirrors of selected volumes.
Uses no host CPU resources – Mirroring done at the storage level
Operating system independent
There is a performance impact on arrays
Limited distance

Can you briefly explain about SRDF/Asynchronous?

The Symmetrix array provides a consistent point-in-time image on the target (R2) device, which is a short period of time behind the source (R1) device. Managed in sessions, SRDF/A transfers data in predefined timed cycles or delta sets to ensure that data at the remote (R2) site is dependent write consistent.
SRDF/A provides a long-distance replication solution with minimal impact onperformance that particularly preserves data consistency with the database.
Promotes efficient link utilization resulting in lower link bandwidth.
Maintains a dependent write consistent copy on the R2 devices at all times.
Supports all current SRDF topologies, including point-to-point and switched fabric.
Requires no additional hardware, such as switches or routers.
Supports all hosts and data emulation types supported by the Symmetrix array
Minimizes the impact imposed on the back-end DA directors.
Provides a performance response time equivalent to writing to local non-SRDF devices.
Allows restore, failover, and failback capability between the R1 and the R2 sites.

What are the factors that effects the SRDF/A implementation?

SRDF link Bandwidth, Symmetrix Cache and Workload.

What is SRDF Automated Replication?

SRDF/AR allows users to automate the sequence of SRDF and TimeFinder mirror operations. The automated sequence, cycle, is performed on a user-defined interval called cycle time. it is usually set to operate in Adaptive Copy mode due to the long distance between local and remote sites. This allows the users to save on network bandwidth thus minimizing the network costs without compromising the integrity of the data.
Allows business restart site to be at any distance away from source
Collaboration of SRDF and TimeFinder commands
Minimizes network costs

How do you change or set the SRDF mode of operations?

Examples:
symrdf -g "DgName" set mode sync
symrdf -cg set mode semi
symrdf -f FileName set mode async
symrdf -g "DgName" set domino on
symrdf -g "DgName" set domino off
symrdf -g "DgName" set mode acp_wp
symrdf -g "DgName" set mode acp_off
symrdf -g prod set mode acp_disk
symrdf -g prod set mode acp_off

What is the background process during the SRDF pairs full establish?

The target (R2) device is Write Disabled to its local host I/O.
Traffic is suspend on the SRDF links.
All the tracks on the target (R2) device are marked invalid.
All tracks on the R2 side are refreshed by the R1 source side. The track tables are merged between the R1 and R2 side.
Traffic is resumed on the SRDF links.

What is the background process during the failback?

The target (R2) device is Write Disabled to its local hosts.
Traffic is suspended on the SRDF links.
If the target side is operational, and there are invalid remote (R2) tracks on the source side (and the force option is specified), the invalid R1 source tracks are marked to refresh from the target side.
The invalid tracks on the source (R1) side are refreshed from the target R2 side. The track tables are merged between the R1 and R2 sides.
Traffic is resumed on the SRDF links.
The source (R1) device is Read/Write Enabled to its local hosts

How will the SRDF restore operation works?

The source (R1) device is Write Disabled to its local hosts.
The target (R2) device is Write Disabled to its local hosts.
Traffic is suspended on the SRDF links.
All tracks on the source (R1) device are marked as invalid.
All R1 tracks are refreshed from the R2 side. The track tables are merged between the R1 and R2 side.
Traffic is resumed on the SRDF links.
The source (R1) device is read/write enabled to its local hosts.

Explain step by step procedure to perform SRDF/S?

SRDF/S normal operations
Creating device groups in source and target Arrays:
symdg -type RDF1 create "SourceDgName"
symdg -type RDF2 create "TargetDgName"

Adding devices R1 and R2 devices to source and target device groups
symld -g "SourceDgName" add dev "SymDevName"
symld -g "TargetDgName" add dev "SymDevName"

Setting SRDF mode of operation:
symrdf -g "DgName" set mode sync

SRDF normal operations:
symrdf -g "DgName" suspend
symrdf -g "DgName" resume

SRDF/S disaster recover operations
symrdf -g "DgName" failover
symrdf -g "DgName" update -remote
symrdf -g "DgName" failback

SRDF/S decission support operations:
symrdf -g "DgName" split
symrdf -g "DgName" restore
symrdf -g "DgName" establish

Explain step by step procedure to perform SRDF/Asynchronous?

Creating RDF group:
symrdf addgrp -label -rdfg "GrpNum" -sid "SymID" -dir "DirNum" -remote_sid –remote_dir -remote_rdfg "RemoteRdfgNum"

Create device pair:
symrdf -file "DevFileName" -sid "SymID" -rdfg "GrpNum" -type r1 -establish -g "DgName" createpair –noprompt

Changing SRDF mode :
symrdf -g "DgName" set mode async -noprompt

Explain step by step procedure to perform SRDF/AR for single hop?

Create a device group:
symdg create "DgName" -type regular

Add the standard device to the device group:
symld -g "DgName" add dev "SymDev"

Associate the R1/BCV device:
symbcv -g "DgName" associate dev "SymBcvDev"

Associate the remote BCV device:
symbcv -g "DgName" associate dev -rdf -bcv

Prepare the mirror states and start the session:
symreplicate -g "DgName" start -option "Path" -setup -consistent

Stop the session:
symreplicate -g "DgName" stop -nop

Restart the session:
symreplicate -g "DgName" restart -nop

OR

Create a device group:
symdg create "DgName" -type regular

Add the standard device to the device group:
symld -g "DgName" add dev "SymDev"

Associate the R1/BCV device:
symbcv -g "DgName" associate dev "SymBcvDev"

Associate the remote BCV device:
symbcv -g "DgName" associate dev "SymBcvDev" -rdf -bcv

Establish the STD and R1/BCV:
symmir -g "DgName" establish -full

Split the STD and R1/BCV:
symmir -g "DgName" split -consistent

Resume SRDF link:
symrdf -g "DgName" resume -bc

Establish the R2 and remote BCV:
symmir -g "DgName" est -full -rdf -bcv

Split the R2 and remote BCV:
symmir -g "DgName" split -full -rdf -bcv

Establish the STD and R1/ BCV:
symmir -g "DgName" establish

How the symstar will be configured?

Uses concurrent and cascaded SRDF/Synchronous and SRDF/Asynchronous links to replicate source data synchronously to a nearby regional site and asynchronously to a distant remote site.

How do you recover suspended or partitioned state session?

Using symrecover command.

What are the access rights required if ACLs enabled?

BASE and CFGSYM access rights required.

Can we migrate the R1 data to larger R2 device?

Yes, we can migrate the R1 data to larger R2 but we can not perform device swap, SRDF/Star operations, we can not restore back to the R1 device and Concatenated meta devices are not supported.

How do you create groups for dynamic RDF pairs in a device file?

Creating dynamic pairs in a device file:
symrdf createpair -file "DevFileName" -sid 55 -rdfg 2 -type rdf1 -invalidate r2 -g "DgName"

What is dynamic R1/R2 swap?

The dynamic R1/R2 swap feature swaps the SRDF personality of the SRDF device designations of a specified device or composite group

What is link limbo and how do you specify?

feature allows you to set a specific length of time for Enginuity to wait when a down link is detected before updating the link status. If the link status is still Not Ready after the link limbo time expires, devices are marked Not Ready to the link.
symrdf -sid 80 -rdfg 4 set link_limbo 60

How do you create/add the dynamic SRDF group?

symrdf addgrp -label "RdfGrpName" -rdfg "RdfGrpNum" -sid "SymID" -dir "DirNum" -remote_rdfg 4 -remote_sid "SymID" -remote_dir "RemDirNum"

How do you add dynamic SRDF pairs to dynamic SRDF group?

symrdf createpair -file "DevFileName" -sid "SymID" -rdfg "RdfGrpNum" -type rdf1 -invalidate r2

What are the Symmetrix Array-wide parameter in SRDF/A?

Maximum SRDF/A Cache Usage and Maximum Host Throttle Time

How do you set the metrics on symmetrix for SRDF/A?

set symmetrix rdfa_cache_percent = 94;
set symmetrix rdfa_host_throttle_time = 0;

What is RDF group session priority parameter?

When SRDF/A needs ts drop sessions when the cache WP limit is reached, the sessions will be dropped starting with priority values of 64 with a setting of 1 being the last to be dropped.

What is the SRDF mode of operation for SRDF/AR?

Adaptive copy mode.

What are the required options for symreplicate options file?

SYMCLI_REPLICATE_HOP_TYPE and one of SYMCLI_REPLICATE_CYCLE or SYMCLI_REPLICATE_CYCLE_DELAY

What is consitency and how to enable?

Consistent split allows us to avoid inconsistencies and restart problems that can occur if you split a database-related BCV without first quiescing the database.
symrdf -g enable

What is automatic tripping and manually tripping of composite group?

Automatic Tripping - Occurs when one or more R1 source devices in an consistency enabled Composite Group cannot propagate data to their corresponding target devices.
Manual Tripping - Occurs when you invoke the symrdf –cg suspend or split command.

Symmetrix TimeFinder - Possible Questions for Interview

What is the purpose of TimeFinder/ Mirror, Clone and SNAP?

TimeFinder/Mirror : Backups and Web content refresh
TimeFinder/Clone : Data warehousing and Application testing
TimeFinder/Snap : Local recovery and 1-hour RPO

What are all possible commands used for TimeFinder Operations (Mirror, Clone and Snapshot)?

Symmir is for timefinder mirror operations
Symclone is for timefinder clone operations
Symsnap is for timefinder snap operations
symconfigure is for devices creation
symdg is fir device group operations
symld is for performing operatoins on devices in a device group
symbcv is for performing operations on devices in a device group
symdev is for performing operations on devices
symcfg is for performing configuratoin related operations

What is the BCV device?

BCV is Business Continuance Volume
Can be dynamically and non-disruptively established and synchronized
Can be split instantly to create “point-in-time” copy.
Uses for the BCV copies can include backup, restore, decision support, and applications testing.

Explain step by step procedure for TimeFinder Mirror Operations?

Establish: Synchronize the standard volume to the BCV volume
Split: Terminate mirror relationship between standard and BCV volumes
Restore: Synchronize contents of BCV volume to the standard volume
Verify: Provide current status of BCV/standard volume relationship.

Creating regular device group
symdg create -type regular

Adding standard devices to the device group
symld -g add dev -sid XXXX

Associating BCV devices to the device group
symbcv -g addl dev -sid XXXX

Establish mirror relationship between STD and BCV devices
symmir -g -full establish -v

Verifying the synchronization status
symmir -g verify -synched

Splitting mirror relationship between STD and BCV devices
symmir -g split

Restoring BCV
symmir -g restore

Verify the restore status
symmir -g verify -synched

What is the status of Source and Target devices at the time of Establish, Split and Restore in mirror operations?

Establish: STD device have R/W access and BCV device is in NR state.
Split : Both STD and BCV will have R/W access
Restore : STD device have R/W access and BCV device is in NR state.

How will synchronization happen when perform establish?

The Symmetrix array checks that both the standard device and the BCV device are the same size, the device specified as the BCV has the BCV attribute, the standard device does not already have a BCV device assigned to it.
If the standard device is a meta head device, then the BCV must also share the same meta device properties. All meta members will be implicitly established along with the meta head device.
The BCV device is set as Not Ready to the host.
The BCV device is assigned as the next available mirror of the standard device.
The contents of the standard device are copied to the BCV.

What is the background process in split operation?

Command validity is checked. For example, the Symmetrix array makes sure that the standard device has an active BCV mirror and that the standard and BCV devices comprise a BCV pair.
I/O is suspended to the standard device until the split operation completes.
Any pending write transactions to the standard device and the BCV device are destaged.
The BCV device is split from the BCV pair.
The BCV device state is changed to Ready, enabling host access through its separate address (BCV001).

What is default option while performing establish?

Incremental is the default action for establish.

What is Power path Split?

Power Path holds I/O during split - Read and write I/O, executed from host doing I/O, affects only one host, does not require independent access to a gatekeeper.

What is ECA (Enginuity Consistent Assist) split?

Symmetrix holds I/O during split - Write I/O (subsequent reads after first write), Executed by any Symmetrix-attached host, multiple host support, requires independent access to a gatekeeper.

What are the precautions we have to take while performing establish?

Host access to BCV devices must be stopped.
Stop application, unmount file system, and deactivate volume group.

What are the precautions we have to take while restoring a mirror?

All access to the STD device must be stopped. Applications must be stopped, file systems must be unmounted, and volume groups must be deactivated when a restore is initiated. Since the host is having read and write access to the standard device, if any application is using the standard volume during a restore, the results would be unpredictable.

What is Protected BCV Establish?

Both M1 and M2 of standard device instantly synchronized with the M1 and M2 of 2-way mirror BCV.
In a 2-way BCV mirror configuration for a normal establish M2 is fixed and can only be updated from M1 after a split.

What is reverse split?

Data will be moved from the M2 mirror of the BCV to its M1 mirror.
During a reverse split, the fixed BCV mirror (M2) will refresh the moving mirror (M1) after the split operation. This is desirable when we need to revert to an older copy of the data that was on the BCV before it was established.

What is Protected BCV Restore?

A protected restore feature allows the contents of a BCV to remain unchanged during and after a restore operation, even while the BCV and the standard are joined.
Restore a BCV to a STD but do not propagate STD writes to the BCV – Used to retain original BCV data after the restore process

How many BCVs can be supported in multi BCV functionality?

Eight BCVs

How many BCVs can be established concurrently to the standard volume?

Two BCVs

Is TimeFinder Mirror Supports concurrent restores?

Concurrent restores are not allowed.

Is the BCV can be mounted to the source host?

BCV mirror can be mounted to same host but there will duplicate disk signatures/volume IDs need to change.

One device can be a member of how many device groups?

Only one device group

Device Groups are host based or Array based?

Host based. If we enable the GNS in symmetrix array then we can create array wide device group.

What is foreground and background instant split?

Foreground split completes instantly and returns a success status to the production.
Background split continues to split the mirror until the split is complete. If the production server tries to access information on a track that has not been split,the system first splits the track and then completes the I/O request

Expbrlain Step by step procedure for TimeFinder Clone Operations?

Create: Create relationship between standard and Clone
Activate: Clone is now active and available immediately for read/write access – Production I/O is processed against standard
Re-Create: Clone is re-attached to Standard for new point-in-time copy (incremental/differential)
Establish: Create and activate
Restore: Re-attached to Standard and incremental or full restore is performed
Terminate: Terminate the relationship between source and target

symdg create -type regular
symld -g add -sid dev XXX1
symld -g add -sid dev XXX2
symclone -g create
symclone -g activate
symclone -g query
symclone -g terminate

What are the different options with clone create and Explain?

CopyOnAccess: Only modified tracks are copied to clone volume after activation
Full Device Copy: Full copy in the background starts after activation
Precopy: Full copy in the background starts after creation
Differential: Used with Full Copy or Precopy (implied Full Copy by default) – Required if recreate clone session is planned – Required if incremental restore is planned.

Can we use STDs as a target for Clone?

Yes, we can use standard or BCV as a clone.

How many CopyOnAccess sessionw symclone will support?

Up to 16 CopyOnAccess sessions

How many concurrent Full copied session clone will support?

Up to 4 concurrent Full Copied sessions

When we have to use –defferential option while create a clone session?

If clone recreate is planned or incremental restore is planned.

What will happen when we activate the clone session?

Places the target in the Read/Write (RW) state
Initiates copying if the -copy option has been specified in the symclone create command
Omitting the -copy option in the symclone create command defers data copying until either tracks on the source are written to or tracks on the target are read or written to

Explain Step by step procedure for TimeFinder Snap Operations?

Create
symsnap –g savedb create DEV001 vdev ld VDEV005 –svp save_db

Activate
symsnap –g savedb activate DEV001 vdev ld VDEV005

Restore
symsnap restore DEV001 vdev ld VDEV005

Terminate
symsnap –g savedb terminate DEV001 vdev ld VDEV005

How the copy session works in symsnap operation?

Once the Time Finder Snap session is activated:
When a host attempts to write to the data on the production volume, the original track is first copied to the “Save Area”, then the write is processed against the production volume. This process of pointers maintains the consistent, point-in-time copy of the data for the ongoing snapshot.

What is the background process while terminating the clone session?

When a copy session is terminated
The virtual device is made not ready
Tracks on the save device(s) are reclaimed if they are not referenced by any other copy session
The copy session structures are freed up

How many snapshots can be created from a single source volume?

Upto 15 snap sessions can be create with source volume.

How many snapshot can be created in multi virtual?

128

What will happen if save area is run out of space?

The target VDEV goes in Not Ready (NR) state, applications beware! Copy-on-write is disabled and the source track is changed.

What is the recommended size of VDEV?

1/600th the size of a source device

How the data will be stored in save devices in a save pool?

Data will be stored in a save pool as a round-robin manner.

EMC Clariion - Possible Questions for Interview

Explain Clariion architecture?

The CLARiiON storage system is based on a modular architecture. The first building block of the architecture is the Disk Processor Enclosure, or DPE. The DPE houses the storage Processor(s) and the first Fibre Channel Arbitrated Loop (FC-AL) disks. Disk Array Enclosures (DAEs) are interconnected using Link Control Cards (LCCs).The module architecture allows the customer to add drives as needed to meet capacity requirements. When more capacity is required, additional disk array enclosures (DAE or DAE2) containing disk modules can be easily added. LCC or Link Control Cards are used to connect shelves of disks. In addition, the LCC monitors the FRUs within the shelf and reports status information to the storage processor. The LCC contains bypass circuitry that allows continued operation of the loop in the event of port failure.

Newer CLARiiON arrays have two processors per Storage Processor, and do not use a DPE. Instead, it utilizes an SPE or Storage Processor Enclosure. The SPE does not contain any disk modules, so it must have at least one DAE2 and a maximum of 16 DAE2s. CLARiiON Architecture is based on intelligent Storage Processors that manage physical drives on the back end and service host requests on the front end, be it Fibre Channel or iSCSI protocols. Storage Processors communicate to each other over the CLARiiON Messaging Interface (CMI). Both the front-end connection to the host and the back-end connection to the physical storage is 2Gb Fibre channel.

What are different types of Clariion models?

CX-200,300,300i,400,500,500i,600 and 700

CX3-10, 20, 40 and CX3-80

CX4-120, 240, 480 and CX4-960

AX Series

FC Series

What are the management tools for Clariion?

NaviCli

NaviSphere Manager

EMC Control Center

SymCli

Minimum number of disks required to create RAID 1/0 raid group?

4,6,10

What is Access Logix?

Access Logix provides LUN masking that allows sharing of storage system.

What are the significant features of Access Logix?

LUN masking.

Presents a virtual storage system.

Maps CLARiiON LUNs (FLARE LUNs) to host LUNs.

Manages the Access Control List.

Manages Initiator Registration Records - Access Logix database entries.

Why Access Logix has to be enabled?

If Access Logix is not enabled all LUNs are presented to all storage system ports. Any host that connects to the storage system will then have access to all of the LUNs on that storage system. In environments where multiple hosts attach to the storage system, this will cause problems. Windows systems may attempt to take ownership of LUNs belonging to other Windows systems, and Unix systems may try to mount Windows LUNs, Access Logix solves these problems by performing LUN masking – it masks certain LUNs from hosts that are not authorized to see them, and presents those LUNs only to the server(s) which are authorized to see them. In effect, it present a ‘virtual storage system’ to each host – the host sees the equivalent of a storage system dedicated to it alone, with only its own LUNs visible to it.

Another task which Access Logix performs is the mapping of CLARiiON LUNs, often called FLARE LUNs or FLUs, to host LUNs. It will determine which physical addresses, in this case the device numbers, each attached host will use for its LUNs. Note that this feature is configurable by the user through the CLI and the GUI. Access to LUNs is controlled by information stored in the Access Logix database, which is resident in a reserved area of CLARiiON disk - the PSM LUN. The Access Logix software manages this database.When host agents in the CLARiiON environment start up, typically shortly after host boot time, they send initiator information to all storage systems they are connected to. This initiator information is stored in the Access Logix database.

How can you check and enable Access Logix?

Right click on Clariion Array select Properties from the drop down menu.

Click on Storage Access Tab

Check whether Access Control Enabled

How many initiators can be connected per port in CX500 CX600?

CX500 – 64 Initiators/Port

CX600 – 32 Initiators/Port

What is CMI? Clariion Message Interface?

Storage Processors communicate to each other over the CLARiiON Messaging Interface (CMI).

What is SP Collects and how do you gather SP Collects?

Spcollect is a Storage Processor based perl script which gathers significant information from the Storage Processor and bundles this information for investigation by engineering.

navicli –h {ip} spcollect {eng mode password} – invoke the spcollects

navicli –h {ip} managefiles –list – to monitor the progress

navicli –h {ip} managefiles –retrieve –file {filename} – to transfer spcollect file to management host.

The managefiles command will transfer the data file to the Navisphere CLI directory where the command was invoked

Explain step by step procedure to assign a LUN to existing Host?

Will check is there any free space is available in existing RAID group as per the required LUN Capacity.

If not available create the new RAID group

Bind the LUN

Will go to the host’s storage group properties and open the LUN tab and add the newly created LUN

Explain step by step procedure for storage provision to the new host?

Installing HBA drivers in new host

Installing NaviAgent

Installing Powerpath if required

Creating Zone, add new zone to zone set, save and enable the zone.

Checking the host connectivity status in the array

Create a new RAID

Bind a LUN (create LUNs as per the host requirement)

Create a metaLUN if required

Create a Storage Group

Add Host and LUN in the storage group properties window

Reboot the host and check the LUN visibility at host-end.

What are pre requisites for LUN migration?

Migration moves data from one LUN to another LUN

Any RAID type to any RAID type, FC to ATA or ATA to FC

Neither LUN may be private LUNs or Hot Spares

Neither LUN may be binding, expanding, or migrating

Either or both may be metaLUNs

Destination LUN may not be in a Stora ge Group

Destination LUN may not be part of SnapView or MirrorView operations

Destination LUN may be larger than Source LUN

How do you create a Meta LUN?

Right Click on LUN > Select Expand > Expand Storage Wizard will appear click on Next > Select the Expansion Type (Stripped or Concatenate) and Click on Next > Confirm the Preserve Data dialog > Select the members (LUN) of Meta and click on Next > Select the User Capacity and click on Next > give the MetaLUN name, Default Owner, Expansion Rate, etc.. and click on Next > Review the Summary and click on Finish.

What is the recommended ration of Read and Write cache?

80% Read and 20% Write Cache

How do you troubleshoot if the Hosts are not registering issue?

1. Right click on clariion array and check the connectivity status whether the initiators are showing. If it is showing check whether the initiators are logged in.

2. If it is showing under connectivity status and registered status showing "NO" then you need to install Agent or else you need to register it manually.

3. If it is Registered and not logged in then you need to check the Zoning side and physical connectivity.

4. if the host initiators are not showing under connectivity status at all then you need check the zoning and physical connectivity. If possible remove the zone and create it back. Once you create the zone dont forget to Enable and Save the config. After this just refresh it.

5. Once all these tasks are fine then you can login to Navisphere and update the array once. Update is over then you can go to connectivity status and check.

What are the significant features of MetaLUN?

A metaLUN is created by combining LUNs

Dynamically increase LUN capacity

Can be done on-line while host I/O is in progress

A LUN can be expanded to create a metaLUN and a metaLUN can be further

expanded by adding additional LUNs

Striped or concatenated

Data is restriped when a striped metaLUN is created

Appears to host as a single LUN

Added to storage group like any other LUN

Can be used with MirrorView, SnapView, or SAN Copy

Supported only on CX family with Navisphere 6.5+

What are the significant features of FLARE operating systems?

FLARE Operating Environment runs in the CLARiiON Storage Processor. I/O handling, RAID algorithms.

End-to-end data protection.

Cache implementation.

Provisioning and resource allocation.

Memory budgets for caching and for snap sessions, mirrors, clones, copies.

Process Scheduling.

Boot Management.

What are the significant features of Cache Memory?

Cache memory on an SP performs two tasks:

Staging: Temporary buffering of current read and write data.

Always performed on each I/O.

Storage: Repository for frequently accessed data.

Maintaining copies of read and write data.

User must explicitly enable this (for both read and write).

Burst Smoothing - Absorb bursts of writes without becoming “disk bound”.

Write cache optimization.

Locality - Merge several writes to the same area into a single operation.

Increases write performance.

Immediacy - Satisfy user requests without going to the disks.

Read cache optimization prefetching of data for sequential reads.

What are the significant features of Clariion Event Monitor?

The Event Monitor GUI is integrated with Navisphere Manager.

Event Monitor is part of the Navisphere Agent.

Monitors for user-configurable events.

Reports those events in user-configurable ways.

May launch other utilities/applications.

Can send SNMP traps to Enterprise Management Platforms.

What are the Clariion Operating Layers?

EMC Control Center/ Clariion Based Applications

Navisphere Manager/NaviCli

FLARE Operating Environment

Clariion Hardware

Explain step by step procedure for LUN migration?

Right Click on the LUN and select migrate from the drop down menu.

Select the migration rate and click on OK.

We can check the status from migration tab in the LUN properties page.

What is the process of LUN Migration Operations?

Data is copied from Source LUN to Destination LUN

- Source stays online and accepts I/O

Destination assumes identity of Source when copy completes

- LUN ID, WWN

- Storage Group membership

Source LUN is unbound after copy completes

The migration process is non-disruptive

– There may be a performance impact

LUN Migration may be cancelled at any point

- Storage system returns to its previous state

What is Private LUN?

The LUN becomes private LUN when you add it to the reserved LUN pool. Since the LUNs in the reserved LUN pool are private LUNs, they cannot belong to storage groups and a server cannot perform I/O to them.

What is Reserved LUN Pool?

The reserved LUN pool works with replication software, such as SnapView, SAN Copy, and MirrorView/A to store data or information required to complete a replication task. The reserved LUN pool consists of one or more private LUNs.

How do you create a user and assign access rights?

Click on Tools > Click on Security > Click on User management

From the User Management windows Click on Add

Give the user name, Role, access level (Global or Local) and password.

How do you monitor Clariion alerts?

Using Clariion Event Monitor

How the Clariion Event Monitor works?

The Event Monitor GUI is integrated with Manager

Event Monitor is part of the Navisphere Agent

Event Monitor is designed to run in the background, without permanent supervision by the operator

Once Event Monitor is initially configured, there is no further need to run UI

Event Monitor relies on the text file navimon.cfg

Self-documenting text file included in Interface Kit

Does not require Event Monitor UI

Monitor Agents run on one or more hosts (or SPs) and watch over the storage systems

When an event is detected, the agent notifies the user As defined by navimon.cfg

Can send SNMP traps to Enterprise Management Platforms.

What are Vault drives and how much capacity they use?

Clariion Platform_____:Vault Drivers____:Vault overhead per drive

CX____________________:0-4______________:6.22 GB

CX3___________________:0-4______________:33 GB

CX4___________________:0-4______________:62 GB

AX4-5_________________:0-3______________:17.4 GB

Vault Drives:

All Clariions have Vault Drives. They are the first five (5) disks in all Clariions. Disks 0_0_0 through 0_0_4. The Vault drives on the Clariion are going to contain some internal information that is pre-configured before you start putting data on the Clariion. Vault Drives contains Vault area, PSM Lun, Flare database Lun and Operating System.

The Vault:

The vault is a ‘save area’ across the first five disks to store write cache from the Storage Processors in the event of a Power Failure to the Clariion, or a Storage Processor Failure.

The PSM Lun:

The Persistent Storage Manager Lun stores the configuration of the Clariion. Such as Disks, Raid Groups, Luns, Access Logix information, SnapView configuration, MirrorView and SanCopy configuration as well.

Flare Database LUN:

The Flare Database LUN will contain the Flare Code that is running on the Clariion. I like to say that it is the application that runs on the Storage Processors that allows the SPs to create the Raid Groups, Bind the LUNs, setup Access Logix, SnapView, MirrorView, SanCopy, etc…

Operating System:

The Operating System of the Storage Processors is stored to the first five drives of the Clariion.

2013-04-03T07:25:00.002-07:00

Cisco SAN Switch

Firmware Update Procedure

SAN-OS contains 2 packages

1) Kickstart – image (linux kernel files)

2) System – image (commands and program files)

Latest firmware is 3.1 (3a)

Direct update to 3.1(3a) is allowed from 2.1 (2b), 2.1(2d), 3.0(1), 3.0(2a), 3.0(3), 3.1(2a), 3.1(3).

Now the firmware flash requires a compact flash card (CF). This CF card is seen in the Cisco SAN-OS as bootflash card.

There is an issue, where if you insert a new firmware CF card, and the CF card checkup utility script finds a bad CF card.

SAW document id: c00876068

The steps to perform firmware update are as follows

# copy running startup-config

This will save the running configuration as the startup configuration

# copy running ftp:// address>/

This will save the running configuration to a FTP site

# show install all impact

This will show the impact of “install all” command

# show install all failure-reason

This will show the reason why “install all” command has failed in past.

# cd bootfalsh:

# dir

This will show the contents of the bootflash (CF) card, and how much space is used and left in the card.

This step is important because the kickstart image is ~ 20MB and system image is ~80 MB. Thus approx ~ 100 MB space in bootflash is required.

# copy ftp:// address>/ m9100-s1ek9-kickstart-mz.3.1.3a.bin bootflash: m9100-s1ek9-kickstart-mz.3.1.3a.bin

This will copy the file “m9100-s1ek9-kickstart-mz.3.1.3a.bin” from the ftp site to Bootflash

# copy ftp:// address>/m9100-s1ek9-mz.3.1.3a.bin bootflash: m9100-s1ek9-mz.3.1.3a.bin

This will copy the file “m9100-s1ek9-mz.3.1.3a.bin” from the ftp site to the Bootflash

# install all kickstart bootflash:m9100-s1ek9-kickstart-mz.3.1.3a.bin

# install all system bootflash:m9100-s1ek9-mz.3.1.3a.bin

This will install the Kickstart and System image from the bootflash.

-----------------------------------------------------------------------------------------------------------

License Key installation

License key is a readable text file (.lic), and it has the serial number of the chassis in readable and encrypted format.

Chassis serial# is also called as host-id

# show license host-id

This show unique id for this host (chassis) for licensing

# show license usage

Shows the status and usage of license.

# show license brief

This shows the list of license files

# copy bootflash:/// ftp:// address>/

This will save the license file to a ftp location

# copy ftp:// address>/ bootflash:///

This will copy the license file from the ftp site to the bootflash

# install license bootflash:///

This will install the license file from the bootflash.

Once installed license, can check the activation of license, by “# show license usage”

# clear license

This will clear the license

Eg:

# show license brief

Enterprise_PKG.lic

FabricManager_lic

# clear license Enterprise_PKG.lic

….

Do you want to continue (y/n) : Y

Clearing license …….done

License is bound to serial #, in case of switch or motherboard replacement new license key needs to be generated.

Brocade Switch Commands

2012-10-31T08:48:00.002-07:00

Brocade Switch Commands:

Check on the case sensitivity using command “help” ( it will demonstrate all the possible commands)

1. firmwareshow – gives firmware version.

2. version – gives version of fabric operating system.

3. fanshow – gives status of fan

4. psshow – gives power supply status.

5. tempshow – gives temp. details, in case of AC failure.

6. chassisshow – gives serial no. of switch.

7. switchshow – gives WWN of switch and ports.

8. nsallshow – shows all name databases details i.e how many servers are connected and to which port. Eg o/p would be (010000) where 01 is switch domain ID, 00 is port no. and 00 is fabric service (ALPA address).

9. fabricprincipal –f 1 – to make a particular switch as primary switch.

10. userconfig - -show –a – will show all accounts in a switch.

11. userconfig - -add username –r rolename – to create an account for particular user and rolename will define the previlleges eg admin, switchadmin, zoneadmin etc..

12. passwd username – to change the password for particular user.

13. userconfig - -delete username – to delete the account for particular user.

14. switchname – displays the name of the switch.

15. switchname “newname” –to change the name of the switch.

16. date “0806102910” – sets date and time where “mm” is 01 – 12 , “dd” is 01 – 31, “hh” is 00 – 23, “mm minutes” is 00 – 59 and “yy” is 00 – 99.

17. tsclockserver “IP of NTP server” – will synchronise the time as what is there in NTP server. It is very important to set the exact time (can’t explain here)and also it has a significance for environment having lot many switches. If time changes say ( day light savings), it would be difficult to change the time manually for each switch but change can be replicated to each switch by above command if there would be and NTP server configured.

18. tstimezone – for changing the timezone.

19. switchstatusshow – displays overall status of the switch.

20. portdisable & portenable , these can be used as a part of troubleshooting, say is HBA is connected to a particular switch port but it is not detecting, then you can try out disabling and enabling the switch port.

21. portshow – displays status of all ports.

22. portperfshow – to check performance of each switch port.

23. portcfgspeed , - to configure speed of particular port.

24. switchcfgspeed - to set switch speed. Where can be 0 : autonegotiated , 1 : 1Gbit/sec, 2 : 2Gbit/sec.

25. portcfgshow – to check the port speed, configuration.

26. uptime – to check the last reboot.

27. nscamshow – shows what exactly is there in cache that has not been saved yet in memory.

28. configupload – to take backup of switch configuration, very important.

29. agtcfgshow – to check is snmp is configured or not.

30. agtcfgset – to configure snmp to send switch alerts to particular server.

These are some of the basic commands for brocade switches, most of them, you wont be using much, Lot many have complete description behind them which can not be explained over here.

Zoning Commands ( Preferably do it GUI unless so sure to do it CLI)

Before knowing the commands, keep in mind the storage (clarion) , servers(to be zoned) , switch (on which to do the zoning), every details. Now assume you have a server named “TRAINING” with two HBA hba1 and hba2 and a storage clarion with FE ports A0. just for eg and to understand the nomenclature, when you work independently.

1. Connect the cable to switch (LC to LC) from server HBA port to one of the switch port.

2. login into the server and find the wwn no. of HBA card ( for solaris – fcinfo & HP-UX – fcutil)

3. login to the switch and match the wwn , run switchshow command.

4. Now create aliases for server ( alicreate “TRAINING_hba1” , “wwn of hba1” )

5. Now create aliases for clarion if not created before and this will be constant throughout ( alicreate “SPA_A0” , “wwn of storage” )

6. Now create the zone ( zonecreate “TRAINING_hba1_SPA_A0” , “TRAINING_hba1 ; SPA_A0” )

7. save the configuratiuon after creating the zone bye cfgsave

8. And then enable the configuration by cfgenable

TRAINING_hba1 – server aliases

SPA_A0 – Storage aliases

TRAINING_hba1_SPA_A0 – Zone name

But if you are creating a zone for the first time in a switch, you would have to create a configuration file before running cfgsave.

Cfgcreate “fabric 1” , “zone name”

fabric 1 is configuration file name.

Run cfgshow to check configuration file.

How to delete a zone

1. cfgremove “fabricname” , “zonename”

2. zonedelete “zonename”

3. alidelete “aliasname”

4. cfgsave

5. cfgenable

2012-09-05T01:29:00.002-07:00

:: MDS-SERIES (CISCO) COMMANDS ::

MDS-SERIES Switch Commands

View = ~ show running-config

show environment ~ shows status of all installed hardware components

show flogi database ~ shows database list of all FLOGI events

show fcns database ~ shows database list of all N-ports logged in

show vsan membership ~ shows list of VSAN members

show interface brief ~ lists the interfaces and status

MDS-SERIES Zoning Commands

config terminal ~Enters configuration terminal

zone name TestZone1 vsan 4 ~ creates a zone

member pwwn 10:01:10:01:10:ab:cd:ef ~ adds node to the zone above

no member pwwn ~deletes member from zone

zoneset name Zoneset1 vsan 4 ~ creates a zoneset

member ~adds zone to the ZoneSet above

no zone name vsan ~ Deletes a zone

zoneset activate name Zoneset1 vsan 4

zone copy active-zoneset full-Zoneset1 vsan 4

copy running-config start-up config ~ copy from source to startup configuration

vsan database ~ go into vsan configuration mode

vsan 4 interface fc3/21 ~move port 21 on module 3 to vsan 4

show zoneset ~ shows all zonesets that are active

show zone vsan <#> ~ shows all zones active in vsan

show zoneset active ~ displays the active zoneset

show vsan ~ shows the vsans on the switch

show zoneset active vsan ~ Shows active zoneset

:: B-SERIES (BROCADE) COMMANDS ::

B-SERIES Switch Commands

switchDisable ~ offline

ipAddrSet ~set the IP address of a Brocade switch

switchShow ~ display switch info

supportShow ~ full detailed switch info

portShow # ~ display port info

nsShow ~ Name server contents

nsAllShow ~ NS for full fabric

fabricShow ~ fabric information

ad --create ~create a new Admin Domain.

ad –apply ~enforce the new Admin Domain configuration.

B-SERIES Zoning Commands

aliCreate “Alias”, “20:00:00:e0:69:40:07:08”

zoneCreate “Zone1”, “20:00:00:e0:69:40:07:08; 50:06:04:82:b8:90:c1:8d”

cfgCreate “Test_cfg”, “Zone1; Zone2”

cfgSave ~ saves zoning information across reboots

cfgEnable “Test_cfg”

zoneShow or cfgShow ~ shows defined and effective zones and configurations

zoneAdd ~ adds a member to a zone

zoneRemove ~ removes a member from a zone

zoneDelete ~ deletes a zone

cfgAdd ~ adds a zone to a zone configuration

cfgRemove ~ removes a zone from a zone configuration

cfgDelete ~ deletes a zone from a zone configuration

cfgClear ~ clears all zoning information/ must disable the effective configuration

::Veritas VM HOST COMMANDS ::

http://www.symantec.com/business/support/documentation.jsp?language=english&view=manuals&pid=15273

Veritas VM Device Commands

vxdisk list ~ List all disks under volume manager control and give there status.

vxdiskadd c1t2d3 ~ add or bring a disk under volume manager control

vxdiskadmin ~ Interactive front end to the vxdisk program

Veritas VM Filesystem commands

vxdisk init ~ Initialize Physical Volume

vxdg init mydg mydg-01=c1t11d0 ~ Create Disk Group

vxassist -g mydg make myvol ~ Create Logical Volume

mkfs -F vxfs /dev/vx/rdsk/mydg/myvol ~ create file system

vxvol -g mydg stopall ~ stop a volume

vxdg deport mydg ~ deport disk group

vxdg import mydg ~ import disk group

vxvol -g mydg startall ~ starting a imported volume

::VMware ESX HOST COMMANDS ::

http://b2v.co.uk/b2vguide2vmware3.htm

VMware ESX Device Commands

esxcfg-info Print out device configurations

esxcfg-module -l List modules loaded in the service console

vmkfstools (-P, -q, -g) ~RDM Target LUN information

esxcfg-advcfg

esxcfg-resgrp

esxcfg-auth ~A uthentication configuration

VMware ESX Storage commands

esxcfg-info –s ~General Storage Info

vdf -h ~Disk Space Utilization

fdisk /dev/sdX ~

esxcfg-scsidevs -A ~prints a mapping between the HBA and the devices

esxcfg-nas -a ~Adds a new NAS file system to the ESX/ESXi host.

esxcfg-boot Manage the boot partitions

esxcfg-dumppart -l Manage the vmkdump partition

esxcfg-mpath –l ~Path information

esxcfg-vmhbadevs –m ~VMKernel-to-Service Console Device Mapping

esxcfg-rescan ~scan for new disks

esxcfg-swiscsi –e ~enable iSCSI initiator

esxcfg-rescan ~Rescan LUNs on SCSI device

esxcfg-resgrp ~Create, delete and list resource groups

vmkpcidivy –q vmhba_devs ~map canonical name to Vmware file system

VMware ESX Networking commands

esxcfg-firewall

esxcfg-nics ~Presents physical NIC information

esxcfg-route ~Enable or disable routing for vmknics

esxcfg-swscsi ~Configures software iSCSIadapters

esxcfg-vmhbadevs ~Maps COS device files to vmhbanames

esxcfg-vmknic ~Create & configure VMkernel NICs

esxcfg-vswif ~Create & configure vswifsfor the COS

esxcfg-vswitch ~Create & configure virtual switches andport groups

:: Windows HOST COMMANDS ::

http://support.microsoft.com/default.aspx/ph/3198?sid=26

Windows 2003 server SP1 Device Commands

SystemInfo ~ Displays detailed configuration information about a computer and its operating system

Shutdown /r /f ~ forced reboot

Netstat ~ Displays active TCP connections, ports on which the computer is listening

mstsc /v: 255.255.255.255 /console ~ launches a Remote desktop Connection

net use \\ComputerName\ShareName\volume ~ Connects a computer to a computer shared resource

FC ~ compares two files and displays the differences

ChkDsk ~ check and repair disk problems

Recover ~ Recover a damaged file from a defective disk.

fcinfo /details ~ if fcinfo is installed ,this will list the HBA’s wwns

Windows 2003 server SP1 LVM Commands

Diskpart rescan ~ Locates new disks that may have been added to the computer

Diskpart list disk ~ Displays a list of disks and information about them,

Diskpart select disk ~ Selects the specified disk and shifts the focus to it.

Diskpart detail disk ~ Displays the properties of the selected disk and the volumes on that disk.

Diskpart create partition primary align=64 ~create a properly offset partition

MountVol ~ Creates, deletes, or lists a volume mount point.

Diskpart assign ~ Assigns a drive letter or mount point to the volume with focus.

Diskpart extend ~ Extends the volume with focus into next contiguous unallocated space

Diskpart import ~ Imports a foreign disk group into the local computer's disk group

Format /FS:filesystem ~ Specifies the type of the file system (FAT, FAT32, or NTFS).

FSutil volume dismount

:: VI COMMANDS ::

Cursor movements

h ~ left one character

l ~ right one character

j ~ down one line

k ~ up one line

w ~ right one word

b ~ back one word

Deleting, Yanking, and Pasting

d ~ delete

x ~ delete character cursor is on

r ~ replace one character

y ~ yank (copy into temporary buffer)

Y ~ yank line cursor is on

p ~ paste below cursor line (deleted or copied text)

Saving and Exiting

u ~ undo last editing command

ZZ ~ save and exit (hold down shift and press "z" twice)

:wq! ~ write and quit even if it is read-only

:: FTP COMMANDS ::

open ~ undo last editing command

close ~ save and exit (hold down shift and press "z" twice)

bin ~set to transfer for binary and text files

hash ~display progress during get

mget ~mutiple get – download files in to current directory

mput ~multiple pu – upload files from current directory

:: AIX/IBM HOST COMMANDS ::

http://publib.boulder.ibm.com/infocenter/pseries/v5r3/index.jsp?topic

AIX Software Installation

/usr/lpp ~ Software Directory

lslpp -L all ~ List installed software

lslpp -f fileset ~ List all files

instfix –i ~ List installed patches

cp *.lpp /usr/sys/inst.images ~ copy lpp software to the install directory

smit installp ~ Install a software package

rmdev ~ Remove a device

AIX Device Commands

lscfg ~ lists all comfigured components

smit or smitty ~ system management utility

lscfg –v l ~ lists all attributes (WWN’s) for a device

emc_cfgmgr ~ configures symmetrix devices

mkbcv ~ makes BCV visable to AIX to avoid locking during boot

(1) chdev -l fcsX -a init_link=pt2pt –P ~ “To change INIT Link flags parameter”

(2) chdev -l fscsiX -a fc_err_recov=fast_fail –P ~ “Fabric Event Error RECOVERY Policy”

(3) cfgmgr –v ~ cofigures devices and optionally installs device software

AIX NFS Commands

exportfs ~Lists all exported filesystems

exportfs -a ~Exports all fs's in /etc/exports file

exportfs -u (filesystem) ~Un-exports a filesystem

mknfs ~Configures and starts NFS services

rmnfs ~Stops and un-configures NFS services

mknfsexp -d /directory ~Creates an NFS export directory

mknfsmnt ~Creates an NFS mount directory

mount hostname:/filesystem /mount-point ~Mount an NFS filesystem

nfso -a ~Display NFS Options

AIX iSCSI Commands

smit iscsi

AIX Filesystem Commands http://the-welters.com/professional/aix/jfs-lvm.html

lsdev –Cc disk ~ Device Listing and status

mkdev ~ configures a disk device masking sue it is available as a physical volume

chdev -l hdisk# -a pv=yes ~ Initialize Physical Volume

lspv -l hdisk# ~ Disk Label

mkvg -y myvg -s 16 hdisk2 ~ groups one or more physical devices into a volume group

mirrorvg ~Creates mirror volumes for all volumes in a volume group.

extendvg myvg hdisk3 hdisk4 ~ Extend Volume Goup

lsvg –l vgname ~ displays volumes, with a specified volume group

mklv -y mylv myvg 16 ~ Make logical volume

mklvcopy hd1 2 hdisk1 ~(2) makes a copy of lv should be followed up by syncvg command

lslv ~ List Logical Volume

chfs -a freeze ~writes all dirty file system metadata and user data to the disk (use before BC & DR)

crfs –v jfs –d mylv –m /myfs

mount ~ mounts a filesystem

varyoffvg myvg ~ Deactivate Volume Group

exportvg myvg ~ Export Volume Group

importvg -y myvg -f /dev/hdisk9 ~ Import Volume Group

varyonvg myvg ~ Activate Volume Group

:: HP/UX HOST COMMANDS ::

http://www.docs.hp.com/en/B2355-90681/index.html

HP/UX Software Installation

sysdef ~ analyzes current running system

swlist –l bundle ~ displays version and type of HP-UX

swlist -l patch ~ List installed patches

swreg –l depot /full/path/to/your/depot_file ~ Register a depot package for install

swinstall ~ Install the Software depot

HP/UX Device Commands

insf –e ~ install special device files

ioscan -fnC disk ~ scans system hardware

sam ~ System administration tool

dd if=/dev/rdsk/c34t15d0 of=/dev/zero count=1 ~ makes HP register with a Clariion thru LUNZ device

navicli –h register ~registers host with Clariion and tests agent install

lsdev –C disk ~ list device drivers in the system

mknod ~ makes a directory, special, or ordinary file

/stand/system ~ system configuration file

HP SAN Commands

fcmsutil /dev/fcd0 ~ List HBA wwn

tdutil /dev/td0 ~ List HBA wwn

HP iSCSI Commands

http://docs.hp.com/en/T1452-90011/T1452-90011.pdf

HP NFS Commands

/etc/exports             ~file controls which file systems are exported to remote hosts and specify options

/exported/directory example.emc.com  ~Exports directory to host example.emc.com (found in /etc/exports)

exportfs –a             ~command to read /etc/export and export filesystem

mount shadowman.emc.com:/misc/export /misc/local ~mount an NFS export from shadowman.emc.com to the dir /misc/local

HP/UX Filesystem commands

pvcreate /dev/rdsk/c1t0d2 ~ creates a physical volume within a LVM volume group

pvdisplay ~ display info about physical volumes within an LVM volume group

ls -l /dev/*/group ~list the minor number of each vg in 6^th field (all not listed are available)

mkdir /dev/myvg ~Create directory entry in /dev for Volume Group

mknod /dev/myvg/group c 64 0x010000 ~ Create a file for Volume Group

vgcreate -s 16 /dev/myvg /dev/dsk/c1t0d0 ~ creates a LVM volume group

vgextend /dev/myvg /dev/dsk/c1t0d1 ~ add disk to VG

vgchange -a y myvg ~ Avtivate VG

vgscan ~ scan physical volumes for LVM volume groups

vgdisplay ~ displays info about LVM volume groups

lvcreate -l 16 -n mylv /dev/myvg ~ creates LVM logical volumes

lvcreate -m mylv /dev/myvg ~ creates mirrored logical volumes

lvdisplay ~ displays LVM logical volumes

newfs /dev/myvg/rmylv ~ Create file system

mount /dev/myvg/mylv /myfs ~ Mount file system

vgchange -a n myvg ~ Deactivate Volume Group

vgexport myvg ~ Export Volume Group

vgimport /dev/myvg /dev/dsk/c1t0d0 ~ Import Volume Group

:: PROCEDURES ::

zone hp server to symm

symmask list hba –v ~to list your servers paths to the symm

symmask –wwn –dir –p add dev ~(use wwn, dir, p values from above command) run command for each hba to FA zone

symmask –wwn –dir –p set heterogeneous on HP_UX ~use wwn from the (symmask list hba –v )

symmask refresh

ioscan –fnC disk

insf –e

symcfg dis

sympd list

To get HPUX to register with Clariion if using NaviAgent

Install NaviAgent

Edit agent.config file

ioscan –fnC disk

insf –e

/sbin/init.d/agent stop

rm /etc/log/HostIdFile.txt

/sbin/init.d/agent start

dd if=/dev/rdsk/c34t15d0 of=/dev/zero count=1 ~ makes HP register with a Clariion thru LUNZ device

navicli –h register ~registers host with Clariion and tests agent install

# rmsf path ( The paths are showing NO_HW or not sensing).

# ioscan -fnc disk (check)

# insf -e

# symcfg discover

# powermt display ( check for any dead path)

# powermt check (checks and corrects dead path).

# powermt config

# powermt save

:: Linux HOST COMMANDS ::

http://www.redhat.com/docs/manuals/enterprise/RHEL-5-manual/en-US/

Linux Software Installation

rpm –hiv

Linux Device Commands

modeinfo lpfc | grep parm ~Emulex hba parameters

modprobe -r lpfc ~unload Emulex driver

lsmod | grep lpfc ~

modprobe lpfc ~ discover new disk

dmsetp ls ~list devices managed my MPIO

/sys/class/scsi_host/host1/issue_lip ~ discover new disk

dmesg |grep scsi ~list scsi devices

/sys/class/scsi_host/host1/scan ~ discover new disk

/usr/sbin/lpfc lun_scan all

Linux FC SAN Commands

hbacmd list ~list Emulex hba

hbacmd allnodeinfo xx:xx:xx:xx:xx:xx:xx:xx ~detail hba wwn info & device list

more /sys/class/scsi_host/hostX/port_name ~ wwn on RHEL4

more /sys/class/fc_host/hostX/port_name ~ wwn on RHEL5

Linux iSCSI Commands

yum install iscsi-initiator-utils ~install iSCSI soft initiator

rpm -q srvadmin-deng iscsi-initiator-utils ~install iSCSI soft initiator

rpm -ql iscsi-initiator-utils ~confiure iSCSI soft initiator

iscsi-iname ~discover iqn

iscsi-ls ~list adapters

iscsiadm -m discovery -t -p 192.168.1.100 ~discover iSCSI target

iscsiadm --mode node --targetname iqn ~

Linux NFS Commands

/etc/exports             ~file controls which file systems are exported to remote hosts and specify options

/exported/directory example.emc.com  ~Exports directory to host example.emc.com (found in /etc/exports)

exportfs –a ~command to read /etc/export and export filesystem

mount shadowman.example.com:/misc/export /misc/local  ~mount an NFS export

redhat-config-nfs   ~RedHat NFS tool

Linux Filesystem commands http://linux.about.com/od/commands/l/blcmdl_8m.htm

pvcreate /dev/emcpowerX ~ initializes PhysicalVolume for later use by the Logical Volume Manager

vgcreate VG_Name /dev/emcpowerX ~ creates a new volume group

lvcreate --size 2000m --name LV_Name /dev/VG_Name ~creates 2000MB logical volume

mkfs -t ext2 /dev/VG_Name/LV_Name ~ Make a file system on a logical volume

mount -t ext2 /dev/VG_Name/LV_Name /mnt/FS_MountPoint ~ mount File system

df –a ~display filesystems

Fdisk /dev/sda ~ partition table manipulation

pvdisplay ~ allows you to see the attributes of one or more physical volumes

pvscan ~ scans all supported LVM block devices in the system for physical volumes

vgdisplay ~display attributes of volume groups

vgextend ~ allows you to add one or more initialized physical volumes

vgscan ~ scan physical volumes for LVM volume groups

vgexport ~make volume groups unknown to the system

vgimport ~make volume groups known to the system

lvdisplay ~display attributes of a logical volume

lvextend ~ Extend logigal volume

fsck ~Command used to check and repair a Linux filesystem

:: SUN/SOLARIS HOST COMMANDS ::

http://developers.sun.com/openstorage/articles/opensolaris_storage_server.html

SOLARIS Software Installation

ptree –a ~ Shows all running processes in a tree format

showrev –p ~ Displays currently installed Solaris patches

prtconf ~ prints system configurations

pkginfo ~ lists installed software packages

pkgadd ~ install software packages

pkgrm ~ removes installed software packages

Solaris Device Commands

cfgadm –a ~ list all

cfgadm –c configure c4 ~ configure StorEdge Leadville driver.(Search for new devices)

devfsadm –vC ~ searches for devices and also cleans up old

update_drv -f sd -d –I         ~  searches for devices

drvconfig ~ generates special device files

reboot -- -r ~ reboots system to discover configuration changes, and rebuild special files

/etc/system ~ system files

/kernel/drv/sd.conf ~ lists of available target ids and luns

/kernel/drc/lpfc.conf ~ used for persistent binding on Emulex (qla22xx.conf for Qlogic)

/var/adm/messages ~ system messages

Solaris iSCSI Commands

iscsiadm add static-config iqn.1999-08.com.array:sn.01234567,192.168.1.3:3260 ~map target

iscsiadm add discovery-address 192.168.1.13:3260

iscsiadm modify discovery --isns enable

iscsiadm list target –vS Target: iqn.1986-03.com

devfsadm -Cv -i iscsi

Solaris FC SAN Commands

fcinfo hba-port ~ Lists information and WWNs

fcinfo remote-port -p 10000000c937694f –ls ~ Lists the remote-port information

fcadm create-fcoe-port -t nxge0 ~Creates a FCoE target port

Solaris NFS Commands

share -F nfs -d "Cartman dir" / share2

mount -F nfs cartman:/share2 /cartman

share -F nfs -o ro=sun.ucs.indiana.edu,rw=teak.uwsg.indiana.edu /reports ~ export (share) /reports

/etc/dfs/dfstab ~ file to edit to make a share permanent

shareall –F nfs ~ command to excute that will read /etc/dfs/dfstab and share to the network

SOLARIS Filesystem Commands

*** Format and lable all devices before using zpool ***

zpool create spoon c3t6d9 ~create & mounts storage pool named spoon and mounts it at /spoon (no slice #)

zpool create spoon mirror emcpower3c  emcpower4c                        ~create a RAID1 storage pool mounted at   /spoon

zpool destroy –f spoon                         ~destroy a zpool

zfs create spoon/fs ~creates ZFS file system spoon/fs, automatically mounted at /spoon/fs.

zpool list                ~list pools

format ~ Disk partitioning and maintenance program

sysdef ~ Device Listing

prtvtoc ~ Disk Label

metadevadm ~ Checks device ID configuration.

metainit ~ Configures volumes.

metastat ~ Displays the status of volumes or hot spare pools.

metaset ~ Administers disk sets.

newfs –v ~ makes a UFS filesystem on disk drive or partition within a diskdrive

:: SOLUTIONS ENABLER COMMANDS ::

Commands to see devices

syminq ~ list all devides seen by host OS

syminq -cids ~ list Clariion devices

syminq hba –fibre ~ list HBA

syminq –pdevfile ~List the location of devices

sympd list ~ lists the Symmetrix devices that the host OS can see

sympd list –vcm ~ lists all the physical device name in the device masking database

symdev list pd ~ lists the Symmetrix devices that the host OS can see

symdisk

Symdev Commands

symdev list ~ list all devices on symm

symdev –sa –p list ~ list devices maped to that one FA

symdev list –noport ~ list devices not mapped to any FE ports

symdev list –clariion

symdev show 0123 -v ~ vebose listing of one device

symdev list -RANGE 0001:0123 –v ~ vebose listing of a rage of devices

Symcfg Commands

symcfg discover ~ discover the storage environment

symcfg list ~ list local and remote symmetrixes

symcfg list –clariion ~ list clariions

symcfg list –v ~ lists whether the Symmetrix director has device masking turned on

symcfg list –FA all list ~ lists all fibre directors in a Symmetrix system

symcfg list -dir all -address -sid 6196 ~ identify the address information for devices

symcfg list -dir all -address -available ~ sid 6196 ~ returns the next available LUN address

symcfg list -lockn all ~ list of visible Symm exclusive locks

symcfg -sid 098712341357 -lockn 15 release ~ release a lock on a Symmetrix array.

Symconfigure Commands

symconfigure –sid -f preview ~ checks file to make sure it is ok to exe

symconfigure –sid -f commit ~ makes the changes from file

symconfigure –sid -f prepare

Symmaskdb Commands

symmaskdb list devs ~ lists all devices accessible to an HBA on a specified Symmetrix system

symmaskdb remove ~ removes the meta member devices

symmaskdb restore ~ restores a database from a specified file

symmaskdb backup ~ backs up a database to a specified file

symmaskdb init ~ deletes and creates a new VCMDB

symmaskdb list assignment ~lists deives already assigned

symmaskdb list no_assignment ~lists deives not yet assigned

Symmask Commands

symmask add devs ~ adds a device to the list of devices that a WWN can access in the database

symmask remove devs ~ removes a device from the list of devices that a WWN can access in the database

symmask delete ~ deletes all access rights for a WWN in the database

symmask replace ~ allows one HBA to replace another

symmask refresh ~ refresh vcmdb to all FA ports

symmask login ~ lists for each Fibre director which hosts and HBA’s are logged in to a Symmetrix system

symmask list HBA’s ~ lists the WWN of the Fibre HBAs on this host

symmask -sid 381 -wwn 50060B000024F9F6 -dir 16C -p 1 set heterogeneous on HP_UX

symmask -sid SymmID set lunoffset on offset base \ -awwn awwn -dir # -p # ~ offset high lun numbers

symmask –wwn add devs -lun xxx ~ allows HVE to be seen by an HBA using different LUN # than in BIN file

symmask –wwn add devs -dynamic_lun ~ allows HVE to be seen by an HBA using different LUN 0+

Other SYMCLI Commands

symsan ~list ports and LUN WWNs seen from a specific Symmetrix director and port

symdg ~ creates/deletes/renames device groups

symld ~ addes & removes devices to a deivce group

symbcv ~ associates/disassociate BCV with device groups

symmir ~ performs (split/establish/restore) BCV mirror commands against device groups

symclone ~ performs (split/establish/restore/activate/terminate/recreate)

symsnap ~ performs (restore/activate/terminate/recreate)

symrdf ~ performs (split/establish/restore/failover/update/failback/suspend/resume) against RDF device groups

symcg ~ Performs operations on a Symmetrix RDF composite group

symrslv ~ Displays logical-to-physical mapping information about a logical object that is stored on a disk.

symstat ~ Displays statistics information about a Symmetrix, any or all directors, a device group, a disk, or a device.

symioctl ~ sends I/O control commands to application

:: NAVICLI COMMANDS ::

navicli –h getsp ~ verify connectivity

navicli –h register ~registers host with Clariion and tests agent install

navicli –h storagegroup ~ list all info about existing groups

navicli –h getrg -lunlist ~ list all existing raid groups and LUNS

navicli –h getdisk ~ shows numbers of disks in storage array

navicli –h getrg ~ shows the number of raid groups

navicli –h get lun ~ lists all the disks

navicli –h storagegroup -list ~ displays storage groups

navicli –h getcache ~ shows the cache

navicli –h storagegroup –create –gname ~ creates a new storage group

navicli –h storagegroup –addhlu –gname -hlu <#> -alu <#> ~ assigns LUNs to storage group

navicli –h storagegroup –connecthost –host -gname ~ assigns host to storage group

:: POWERPATH COMMANDS ::

powermt ~ manage powerpath environment

powercf ~ configure powerpath devices

powermt display dev=all ~display PowerPath controlled devices

powermt check

powermt config

emcpreg ~ manage powerpath license registration

emcpupgrade ~ convert powerpath configuration files

:: INQ ::

ftp://ftp.lss.emc.com/pub/symm3000/inquiry/

Inq –h ~ list options and syntax

Inq –hba ~ list hba wwn

Inq –btl ~ display Bus Target and Lun

Inq –show_vol ~ display Symmetrix Volume Number.

Inq –winvol ~ show Windows filesystems

Inq -clariion ~ display CLARiiON device information

inq -dev \\.\physicaldrive1 -page0 ~ Raw unformatted data on a single device

Tips for getting and acing your interview (for students & recent graduates)

2011-10-31T10:33:00.000-07:00

Update your resume with your most recent work or student project experience. Employer want to see your ambition in action.Do your homework on the prospective company and jot down some questions to ask during an interview/meeting.

Attributes companies look for and sample questions

Problem-solving

Explain how you recently anticipated a problem before it occurred.
Cite an instance in which you had to solve a problem with little guidance or direction.

Teaming

Describe a time when you put the needs of a group before your own when completing a task.
Recount a situation in which you had difficulties working with someone on a project. What did you do to improve the relationship?

Results-driven

Describe a difficult or complex project where you provided realistic time frames for task completion and regularly updated management on progress.
What goals do you have for your career? How do you plan to achieve those goals?

Accountability

Cite an instance when a group you were leading failed or did not meet expectations. How did you take responsibility?
Provide an example of when you had two projects competing for your time. How did you prioritize? Were you able to keep your commitment to both projects?

Initiative

Recall a time when you sought ways to create and improve the way in which work gets done.
When assigned a project, how do you approach it? Do you seek to merely meet the objectives, or do you make it your goal to go above and beyond? Give an example.

Adaptability

Describe a situation from which you learned quickly and overcame adversity or failure. Give an example of a time when the rules or structure of a project changed at the last minute. How did you react?

Integrity

Cite an example of a situation where you admitted making a mistake. How did you approach the situation and what was the response?
Recount an instance when your integrity was tested (i.e., keeping a promise or confidence, being truthful).

Sense of urgency

Describe an instance when you had to anticipate obstacles in your action plan. What contingency plans did you prepare? What was the result?
Recount a situation when you faced demanding deadlines. What steps did you take to ensure that you achieved your goals by the deadline?

Communication

Provide an example of when you had to tailor a presentation or message for a certain group of people.
Describe a situation in which you successfully communicated with a difficult person.

Driving change

Give an example of a situation in which you recognized the need for change. How did you adapt your style to obtain results?
Recount a situation in which you constructively challenged an established procedure or way of doing things.

Interview questions‏

2011-02-27T05:27:00.000-08:00

The ground rule during a behavioral interview is to be polite, humble, be open to feedback and keeping your answers short and crisp. This should help you to get a fair idea on how to frame or format your answers for the most delicate and crucial questions( even the most stupid ones).

Some common questions asked in today's interviews:-

1) Why should I hire you. (Most common and the most stupid question asked nowadays).

The answer should be "you are the best person for the job". But this statement alone is not sufficient. You need to back it up with the outstanding and unique qualities in you.

Detailed answer: I realise that there are likely other candidates who also have the ability to do this job. Yet I bring an additional quality that makes me the best person for the job i.e. "My passion for excellence." I am passionately committed to to producing truly world class results.

Quote an example where you were bestowed with a job and you handled the same with excellence. You can talk about a project which you handled during your MBA course. You were asked to lead the project and how effectively you executed through unique means… Talk about the challenges and hurdles you faced while you worked on it and the steps you took to overcome it.

Common challenges in a project includes team building, collection of data from different sources, knowledge transfer (understanding the project- aims and objectives), co- ordination and completion within the specified time frame.

Another Answer would be : "Because I would be an asset to your organization. I'm loyal, tenacious, motivated, and I learn fast. I'm someone who could be very productive very quickly."

2) What are your strengths?

I am a kind of a person who is committed to work, open to constructive feedback, ability to foresee things, a good decision maker and above all a good TEAM PLAYER.

Immediately the next question would be to give examples for your team playing and decision making skills.

Answer: I strongly believe that Effective teams are an intermediary goal towards getting good, sustainable results .

Examples for Team playing skills: A very good example of team playing skills is knowledge sharing. (happens on a daily basis). When working on projects, different team members are prone to get different updates and information regarding the subject being researched upon. To ensure that every team member is in sync or aware of the latest updates and any new findings, knowledge sharing should happen on a daily basis. If member X finds a unique solution for an issue in question, then it is the duty of member X to share that solution to all other team members. When a similar issue reoccurs, all team members are well aware of the solution. This reduces the time and cost in finding the solution to a great extent.

Secondly, the performance of an individual is calculated based on the team's scores and not the individual scores. . A deeper understanding of each team member's strengths and weaknesses and helping them to overcome those weaknesses is also an example.

Its always WE and not ME

Examples for Decision making skills: A good decision maker is one who gathers input from his fellow team members and come out with the best decision after rigorous analysis. A decision is made after carefully analysing the pros and cons of the results. But there are times when a decision has to be taken individually. But even during those situations, a quick calculation of the possible outcomes is done and then a decision is made.

Quote an example where you took your team's help to take a decision. Aslo quote an example where you were asked to take an individual decision. ( no time available for discussion and things).

Ability to foresee things will help you a lot when working on projects. You are well aware of what is the outcome of a particular task being performed. This will help you to get rid of the chaos and mental traumas during the final stages of the project.

3) What is your greatest weakness? ( The most important one..)

Do not reveal any weaknesses even though if you have one. The interviewer is not looking at answers like I become nervous very often, I work too hard to meet dead lines, I am poor at public speaking, etc. A strength should actually be projected as a weakness.

The best answer would be : I have had trouble in the past with planning and prioritization. However, I'm now taking steps to correct this. Nowadays I prepare a to-do list of the tasks which I need to execute. This helps me in getting rid of issues that come up due to improper planning. I am able to execute my tasks effectively.

Another example would be : I am a kind of a person who expects 100% perfection in the tasks I undertake. However at times it happens that the job I undertook did not yield 100% results. These kind of results (anything less than 100%) make me disappointed and disheartened to some extent. However I do a detailed study of what went wrong, accept constructive feedbacks from my folks and then work on those gray areas. This had helped me a lot to achieve 100% results in all my undertakings.

Note : keep the answer to this question short and crisp. Lengthy answers to this question may prove fatal. First prepare the answer before you speak. Buy some time from the interviewer if he/she asks for an example. Whatever you speak should be in sequence and completely related to the previous line.

4) If I were to ask your managers/professors to describe you, what would they say?

My manager (professor) would say that I am one of the most flexible and dependant person in his team.

Answers like "I believe he would say I'm a very energetic person, that I'm results oriented and one of the best people he has ever worked with." is very well accepted in the interview.

5) What qualities you feel a successful manager should have?

Focus on two words: Leadership and vision.

Here is a sample of how to respond: "The key quality in a successful manager should be leadership--the ability to be the visionary for the people who are working under them. The person who can set the course and direction for subordinates. The highest calling of a true leader is inspiring others to reach the highest of their abilities.

6) What are your goals and objectives in life.

Goals are broadly classified into two categories. Short term goals and Long term goals.

Short term goals: My short term goal is to join a Company like XYZ and become a successful business analyst within the shortest span.

Long term goals : The answer should be…... "I have learned that long-term goals are best achieved when I break them into shorter goals. My short-term goal is to find a position that will put me in a forward-moving company with solid performance and future projections. As part of a team, I want to add value and continue to grow the company. My long-term goal will depend on where the company goes. My plan is to move into a position of responsibility where I can lead a team."

If you want to be specific about a role which you would like to acquire…. Then find out to what extent a business analyst can grow… I mean the various growth options for a business analyst role.

7) Where would you like to see yourself 5 years down the line ?

: "Within five years, I would like to become the very best analyst your company has on staff. I want to work toward becoming the expert that others rely upon. And in doing so, I feel I'll be fully prepared to take on any greater responsibilities which might be presented in the long term.

Mention some steps you are currently taking to achieve that level. Examples would be interaction with various executives,reading books, media, attending expert lectures etc.

8) Why do you want to join xyz company and why not other companies.

I have done a lot of research on companies to find out which is the best and the right one for me to pursue my career. I shortlisted a few companies and xyz is my first choice or xyz tops my list.

Why xyz tops the list?

I request you to go thru the company site and collect some articles about the company's success stories, employee satisfaction, technical exposure and growth opportunities. This shows that you have done your homework and will create a positive impression.

9) What will you do if I don't hire you?

I will consider myself as unfortunate, however I will not lose heart. I will work on the constructive feedback provided and will give a defenite try during the next eligible attempt.

10) How long will you stay with us?

I will stay with your company as long as we (employee and the respective manager) both feel that I AM contributing, achieving and growing.

11) What motivates you?"

"A job well done." "A challenge." "Interesting work/technology." Any or all of these answers work

12) What are your salary expectations.

Salary is not my primary consideration. Of course, I have to pay the bills. I'd be open to any reasonable offer." Pause and maintain direct eye contact, even if it seems like forever. Do not be the first one to flinch. Do not over-talk. Be prepared for a long silence. Let the manager be the first to present a figure. It will give you power and control.

If forced to give a specific number, never give a broad range -- you will usually be offered the low end. Instead, be as precise as possible: "I'd be open to something in the low-fifties (or mid-forties, high-seventies, whatever)." Giving such a specific number presumes you've researched the local job market and know what people with your skills are making.

13) Can you work under pressure?"

Yes, I usually find it stimulating. However, I believe in planning and time management in order to reduce panic.

14) "What are your biggest accomplishments?"

Keep your answers job-related, a number of achievements should spring to mind. Do not exaggerate contributions to major projects. You might begin your reply with: "Although I feel my biggest accomplishments are ahead of me, I am proud of my involvement with…….I made my contribution as part of that team and learned a lot in the process. We did it with hard work, concentration, and an eye for the bottom line." Always remember to quantify your achievements.

You can use this as a reference to answer any kind of non- technical questions. Be prepared with relevant examples and cite them wherever possible
Some general tips.

Be confident.
Have eye to eye contact.
Do not Panic
Define your goals and objectives well in advance.
Do not get into arguments.
Have a set of questions for the interviewer. ( to be asked in the end)
Examples: How would you describe the responsibilities of the position? What are the prospects for growth and advancement.? What is the company's management style?
Thank the interviewer for his precious time.

All The Best !

Exchange Server 2003_Technical Interview Questions‏

2011-02-27T05:15:00.000-08:00

Referencehttp://exchange-server-2003.blogspot.com/
http://active-directory-services.blogspot.com/

Exchange 2007 CBT nuggets to below link:

http://cid-2ffebcd4dcbfdeca.office.live.com/browse.aspx/Public

Microsoft Exchange Server is a messaging and collaborative software product developed by Microsoft. It is part of the Microsoft Servers line of server products and is widely used by enterprises using Microsoft infrastructure solutions. Exchange's major features consist of electronic mail, calendaring, contacts and tasks, and support for the mobile and web-based access to information, as well as supporting data storage.

*************************

What are the different Exchange 2003 versions?

Exchange Server 2003 is available in two versions, Standard Edition and Enterprise Edition.

*************************

What are the main differences between Exchange 5.5 and Exchange 2000/2003?

Exchange 5.5 does not integrate with the NT4 domain or the Windows 2000/2003 Active Directory in a meaningful way. A single user could be associated with several different mailboxes. Exchange 2000/2003/2007 integrates tightly with Active Directory, and there is a 1:1 relationship between mailboxes and AD user accounts. There are other differences, depending on whether you have a standard or enterprise version as it relates to maximum database size, but the directory integration is probably the biggest difference.

*************************

To which group does the account that runs the initial ForestPrep in the domain with the Schema Master need to belong so that the AD schema can be extended properly?

Enterprise Administrator

Schema Administrator

*************************

To run a DomainPrep on a domain for the first time, a user account needs to be a member of which group?

Domain Administrator

*************************

Which of the servers does the system that will host the first Exchange Server 2003 server in a forest need to be able to contact during installation?

DNS Server

Schema Master

Domain Controller

DNS server is required so that the system on which the Exchange Server is being installed can locate the Schema Master and a domain controller.

*************************

What are the benefits of running Exchange Server 2003 in native, rather than mixed mode?

User mailboxes can moved between administrative groups.

LDAP query-based distribution groups can be used.

The default routing protocol is SMTP

You can move Exchange Server 2003 computers from one routing group to another.

Exchange Problems and Basic troubleshooting checklist

2011-02-27T05:06:00.000-08:00

Issue 1:
System Attendant service is not starting.

Solution.

 Check for the event ids in the application log.

 Check whether the account used to start the service is a “Local system account” by looking at the properties of SA service from the event viewer.(Eventvwr)

 Check whether the account used to login is a “Domain administrator account” by using “SET” or “SET l” command from the DOS Prompt. The account should have the full permissions on the Exchange organization.

 Check whether the server object (Exchange server name) has full control permissions on the server container object in the Active directory using Adsiedit console. http://support.microsoft.com/kb/297295

 Check whether we have Exchange Enterprise servers group and Exchange Domain servers group listed in the “Users” container from the ADUC console.

 Check whether the Exchange domain servers group is a member of Exchange Enterprise servers group.

 Check whether the Exchange server is a member of Exchange Domain servers group.

 Check whether the Enterprise Exchange server group is a member of “Manage auditing and Security log right” using ADUC. http://support.microsoft.com/kb/314294

Right click on Domain controllers -> properties -> Group policy tab -> Edit - > Computer configuration -> Security - > local policies -> user rights assignment -> Managing audit and security log -> Properties.

 Run DomainPrep command from the Exchange CD to reset the permissions and to recreate the security groups for the Exchange in the Active directory.

Setup.exe /domainprep from the run command.

If the problem persists, we need to check the functionality of the Global catalog servers and the Domain controllers. We need to have atleast one GC server in the site to start the SA service successfully.

To start the Exchange services DNS and Active directory should be inplace.

Use the following commands and tools to test the functionality of Domain controllers and DNS.

 Dcdiag /s > output file name to run the command on a member server). Just type Dcdiag if running on a DC. We need to execute the command for each DC. If the output contains any replication error or DNS errors then the issue is with the Active directory.

 Check for the event id’s 2101 or 2102 in the application or system log for Topology discovery errors. (If the topology discovery is successful an event id: 2080 will be generated in the app log).

 Verify for the FSMO roles on the Domain controllers using the following command.

Netdom query FSMO

 Nltest /DCLIST: - Get list of DC's for

 To test the connectivity between Exchange and DC’s execute the following command.

Netdiag > output file name

 Run the following command to test the DNS functionality:

Netdiag /test: DNS

 To check the Exchange site run the following command:

Nltest /dsgetsite

 To check the DC and the GC functionality:

Nltest /dsgetdc :< FQDN>

 Copy “Policytest” tool from the Exchange CD and execute the command “Policytest.exe” from the DOS prompt. http://support.microsoft.com/kb/314294

If failed to found the privileges to the DC then run the command “Domainprep”

From the Exchange server CD. http://support.microsoft.com/?kbid=328662

 Use “replmon.exe” GUI tool to troubleshoot the replication problems. Also we can use “repadmin” to troubleshoot the replication problems of DControllers.

Articles for reference:
================

http://support.microsoft.com/?kbid=821907

http://support.microsoft.com/?kbid=325964

http://support.microsoft.com/?kbid=280432

http://support.microsoft.com/?kbid=245024

http://support.microsoft.com/?kbid=251640

http://support.microsoft.com/?kbid=327844

http://support.microsoft.com/?kbid=906154

http://support.microsoft.com/?id=822590

Overview of nltest command:

http://support.microsoft.com/default.aspx?scid=kb;EN-US;158148

Overview of netdiag and dcdiag commands:

http://support.microsoft.com/kb/321708

http://support.microsoft.com/?kbid=265706

========================================================================
Issue 2:

Mailbox store and Public folder stores not mounting (Database not mounting).

Possible causes:

 Exchange services are not started.

 Stores are in Inconsistent state.

 Insufficient permissions to mount the stores.

 Exchange databases reached 16 GB limitation (Standard edition)

 Insufficient Disk space causing the stores to mount.

Solution:

 Check whether the Exchange services are started successfully. (System Attendant service and Information store service)
If the System Attendant service is not started perform the troubleshooting steps stated for Issue 2.

If the SA is started and Information store is not started, the follow the below troubleshooting steps:

• Check the application log for Event ids.

• Check whether we are using local system account to start the service.

• Check out whether the Exchsrvr folder and the Inetsrv folder is excluded from the “Anti-virus Exclusions list”.

• Check whether the Anti virus is scanning the Exchange databases in the back ground. If possible stop the Anti virus service or disable the background scanning.

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeIS\VirusScan (In the Value Data field, change the value to 0.) 0 means disabled, 1 means enabled.

If the problem persists, check the “STATE” field of the service. Whether the service is in starting state or the service itself is not starting. If the service is “Crashing or is in Hanging mode” then follow the troubleshooting steps for Issue 5.

If the Information Store service started successfully then we need to verify the permissions and the consistency of the Exchange databases.

 Checking the permissions and the consistency of the Exchange databases.

 Minimum permissions required for mailbox store and public folder store: (check on the mail box and public folder store from ESM)

• Administrators group - Full Control

• Authenticated Users group - Read and Execute, List Folder Contents, and Read

• Creator Owner - None

• Server Operators group - Modify, Read and Execute, List Folder Contents, Read, and Write

• System account - Full Control

 Check whether the Exchange computer has full control permissions on the mail box store.

 Check for the above permissions on the MDBDATA folder.

 Check whether the inherited permission check box is enabled on the mail box store.

 Check for the consistency of the Exchange databases (Priv1.edb and Pub1.edb) by using below commands:

C:\Program files\Exchsrvr\Bin> eseutil /mh

C:\Program files\Exchsrvr\Bin> eseutil /mh

Note: We need to run the “Eseutil” command from the BIN folder.

• Check for the value in “State” field /mh command. Either it should show “Consistent - Clean shutdown” or “Inconsistent - Dirty shutdown”.

• If the database is “Consistent” then verify for the permissions listed above or look for the event ids in the application log. Also, try removing or stopping the anti-virus software.

• If the database is “In-consistent” then verify for the “Log required field” in the output of /mh command.

• Find the check point value of the last log file by using the below command: (check point file tells the last log file committed to the database)

C:\Program files\Exchsrvr\Bin> eseutil /mk

If all the required log files are present in the log files folder:

• If the required log files are available in the Log files folder then do a soft recovery to play the log files using eseutil command.

• Before doing soft recovery check the integrity of the log files whether all the log files are in sequence and the files are not corrupted by using the below command:

C:\Program files\Exchsrvr\Bin> eseutil /ml (Do not mention .log in the command path”

• Keep only the required log files in the log files folder and move all the log files to the temp folder.

• Performing soft recovery to play the required log files in the log files folder using below command:

http://www.microsoft.com/technet/prodtechnol/exchange/Analyzer/f8faaa6d-7213-4271-9ba3-a2c4274f091d.mspx

The complete syntax for the Eseutil.exe soft recovery function, listing all possible switches, is:

ESEUTIL /r enn /L[path to log files] /s[path to checkpoint file] /d[path to database file] /i

Example: ESEUTIL /r e01 /Lf:\mdbdata /sc:\exchsrvr\mdbdata /dg:\mdbdata /i

We can use the switch “/t” with the eseutil command to ignore the log files available 0n the hard drive (In MDBDATA) folder.

Note: In the Application event log, an Extensible Storage Engine (ESE) event ID 204 information message is logged to indicate the start of recovery, and then a series of ESE event ID 301 information messages are logged. These information messages indicate the exact log numbers that are recovered. Finally, an ESE event ID 205 information message is logged to indicate that the recovery process is complete.

Note: We can also dismount and remount the mail box store to replay the required log files in the log file folder.

If any of the required log file is missing:

 Verify any log file is quarantined by the anti virus software. If any log file is quarantined restore the log file to the original location and perform soft recovery.

 Restore the databases from the backup and play the log files from Restore.env file. (By default log files are restored to a TEMP folder with the file name “Restore.env”). After playing the log files from Restore.env file we can also play the log files available on hard disk.

To see the contents of the Restore.env file, execute the below command:

C:\Program files\Exchsrvr\Bin> eseutil /cm (Do not mention the file name “Restore.env” in the command line.

To play the log files present in Restore.env file, execute the below command:

C:\Program files\Exchsrvr\Bin> eseutil /cc (Do not mention the file name “Restore.env” in the command line.

Performing hard repair if the backup is not available

 If backup is not available, then we need to do a hard repair on the Exchange databases. We need to follow the below steps to do hard repair on the databases followed by defragmentation and running Isinteg command.

Description of Eseutil /p command:

http://support.microsoft.com/?id=259851

C:\Program files\Exchsrvr\Bin> eseutil /p

C:\Program files\Exchsrvr\Bin> eseutil /p

Description of Eseutil /d command:

http://support.microsoft.com/?kbid=192185

C:\Program files\Exchsrvr\Bin> eseutil /d

C:\Program files\Exchsrvr\Bin> eseutil /d

Note: After doing offline defragmentation we need to move all the log files in the log file folder to a Temp folder. Mount the stores and dismount the stores to run Isinteg command. We need to take the backup of the Exchange databases after performing the offline defragmentation because the signature of the databases changes after defragmentation.

Description of Isinteg command:

http://support.microsoft.com/?id=301460

C:\Program files\Exchsrvr\Bin> isinteg –s -fix –test alltests

How to run Eseutil on a computer without Exchange Server:

http://support.microsoft.com/?id=244525

If the database is reached 16 GB limitation follow the steps given in the below KB article:

http://support.microsoft.com/?id=828070

For more information on 16 GB limitation proceed to Issue 6.

Articles for reference:
================

Top 10 Database Mounting Issues and Their Solutions:

http://www.microsoft.com/technet/prodtechnol/exchange/2003/hd.mspx

Information store does not mount with 0xfffff745 and -2235 errors:

http://support.microsoft.com/?id=307242

Information Stores Do Not Mount After You Use the "/disasterrecovery" Switch:

http://support.microsoft.com/?id=285169

How Circular Logging Affects the Use of Transaction Logs:

http://support.microsoft.com/?kbid=147524

How and when to manipulate Exchange transaction logs in disaster recovery:

http://support.microsoft.com/?kbid=812592

How the Restore in Progress Registry Key Works (Exchange 5.5):

http://support.microsoft.com/?kbid=200941

=========================================================================

Issue 3:

Information store service is not starting or the IS service is crashing or in hanging state.

Possible causes:

 Anti virus scanning the Exchange databases.

 Active directory issue.

Solution:

• Check the application log for Event ids.

• Check whether we are using local system account to start the service.

• Check out whether the Exchsrvr folder and the Inetsrv folder is excluded from the “Anti-virus Exclusions list”.

• Check whether the Anti virus is scanning the Exchange databases in the back ground. If possible stop the Anti virus service or disable the background scanning.

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeIS\VirusScan (In the Value Data field, change the value to 0.) 0 means disabled, 1 means enabled.

If the problem persists, check the “STATE” field of the service. Whether the service is in starting state or the service itself is not starting. If the service is “Crashing or is in Hanging mode” then follow the troubleshooting steps.

If the Information store service is crashing or hanging(starting state):

To assist in troubleshooting Exchange 2000 Server information store issues, you can enable information store logging. This writes verbose logging information to a Store.log file that is created in the Exchsrvr\Bin folder.

This logging is enabled by default in debug versions of the Store.exe file, but it is disabled in customer retail (RTL) versions.

MORE INFORMATION

To enable information store tracing capabilities in retail versions of the Store.exe file you need to add a new key to the registry.
1. Copy \\exutils\exes\storeitp\store.ttd to the Exchsrvr\Bin folder.

2. Start the Registry Editor utility (Regedt32.exe).

3. Locate the following key in the registry:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeIS\ParametersSystem

4. On the Edit menu, click Add Value, and then add the following registry value:

Value Name: Enable Tracing

Data Type: REG_DWORD

Value: 0x1

5. Quit the Registry Editor.

The Information Store will begin to log the debug traces in the Store.log file in the \Exchsrvr\Bin folder (this may take up to one minute to begin its logging mechanism). You do not have to stop and restart the information store for these changes to take effect.

NOTE: This pre-made Store.ttd file contains the generic tracing information. You can create a custom Store.ttd file on your own, but this requires you to install the debug build of Store.exe, or use the StartITP.exe utility to enable the specific tracing that you require.

For additional information about how to use StartITP.exe, click the article number below to view the article in the Microsoft Knowledge Base:

250913 How to Open a Store ITP Window against a Retail Build of Store.exe (Internal KB)

The debug build of the Store.exe file is located at:
Standard version:
file://exrel/RELEASE/boneyard/Ex60RTM/server/standard/std/dbg/USA/setup/i386/exchange/bin

Enterprise Version:
file://exrel/RELEASE/boneyard/Ex60RTM/server/enterprise/ent/dbg/USA/setup/i386/exchange/bin

For example, start the debug build of the Store.exe file from the command prompt, click Debug , click Trace Info , and then, under TAG Numbers , click to select the 1 and 2 check boxes.

The information store creates a TTD file in the Exchsrvr\Bin folder.

You can also copy the TTD file from a different server.

The information store begins to log the traces in the Store.log file in the Bin folder. You do not have to stop and restart the information store.

You can limit store tracing for individual users. To do so:

1. Locate the following key in the registry:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeIS\ParametersSystem

2. On the Edit menu, click Add Value, and then add the following registry key:
Value Name: Trace User LegacyDN
Data Type: REG_SZ
Value: legacyExchangeDN of the user that you want to trace

Per-User Tracing Feature Added to Exchange 2000 Server Service Pack 2 (SP2):

http://support.microsoft.com/default.aspx?scid=kb;en-us;296624

Enabling store tracing:
=======================

1. Make sure that the Microsoft Exchange Information Store service is stopped.
2. Click Start, click Run, type regedit, and then click OK.
3. In Registry Editor, locate the following subkey:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeIS\ParametersSystem

4. On the Edit menu, point to New, click DWORD Value, and then follow these steps:
a. In the Value Name box, type Enable Tracing .
b. In the Data Type box, type REG_DWORD .
c. In the Data Value box, type 1 .

5. Try to start the Microsoft Exchange Information Store service again.
 We can also use ADPLUS tool to take the dump of store.exe process. Below is the detailed action plan for taking the dump of Store.exe for IS service crashing or hanging using ADPLUS tool.

Before the crash occurs

Step I: Download and install the Microsoft Debuggers

NOTE: You do not have to install the debug tools on your Exchange server. It can be installed on a workstation then copied to the the Exchange server.

• Go to http://www.microsoft.com/whdc/devtools/debugging/installx86.mspx

• In the Installing Debugging Tools for Windows section, follow steps 1 and 2.

• In the File Download dialog box, Select Save and save file to the local hard drive.

• Once downloaded, navigate to the folder and double click the executable to install.

Step 2: Run Adplus.vbs on the Exchange server console (not through Terminal Services).

• Open a command prompt by going to Start, Run and enter the syntax: CMD

• Navigate to the debuggers folder (Default is c:\Program Files\Debugging Tools For Windows):

• Enter the syntax:

cscript adplus.vbs –crash(-hang) -pn store.exe -NoDumpOnFirst -o c:\store _DumpFile

• Click "OK" to the Adplus Warning stating "An _NT_SYMBOLS_PATH environment variable is not set..."

• At this point, Adplus will attach a debugger to the process and wait for an Access Violation.

• Once an Access Violation occurs, the debugger will be invoked and a dump file will be created.

• The folder Store_DumpFile will be automatically created and all data files will be placed in the folder.

Visit the following web site for instructions and to download the ADPLUS tool:

http://support.microsoft.com/default.aspx?scid=kb;en-us;286350

Articles for Reference:
=============

How to Collect Diagnostic Data to Help Troubleshoot Information Store Issues:

http://support.microsoft.com/?kbid=907783

How to Collect Diagnostic Data for Information Store Troubleshooting:

http://support.microsoft.com/?kbid=257725

Information Store Does Not Start with Service-Specific Error 0 (Zero) http://support.microsoft.com/?kbid=283179

Per-User Tracing Feature Added to Exchange 2000 Server Service Pack 2 (SP2):

http://support.microsoft.com/?kbid=296624

The Information Store service and Outlook 2003 crash intermittently when Outlook 2003 clients connect to a mailbox on an Exchange 5.5 server http://support.microsoft.com/?kbid=834466

Exchange Server 5.5 Post-SP3 Information Store Fixes Available:

http://support.microsoft.com/?kbid=248838

=========================================================================
¬Issue 4:

Logs files are not purged after taking full backup.

Possible causes:

 Log files may get corrupted.

 Selecting wrong backup type (Differential, Copy or Daily)

 Either Information store or Public folder store is not selected during backup.

Solution:

 Try taking the backup using NTBackup software.

• Select Information store and Public folder store during backup.

• Select the option full backup in the backup software.

Once the backup completes all the log files get deleted automatically. If the log files are not purged during full online backup then move the log files to the Temp folder. Try sending few e-mails to create new log files; to isolate the issue whether the problem is with the old log files get corrupted.

If the problem persists, verify whether the backup was successful. Also check the application and system logs for any event ids and errors and proceed with the further troubleshooting steps as necessary.

=========================================================================
Issue 5:

Problem replicating Public folders from one Exchange server to other server.

Possible Causes:

 Mail flow is not working between the servers.

 Public folder store is not stamped with the proxy address.

 Replicas are not added to the public folders.

 Network connectivity issues.

Solution:

Follow the steps given in the below KB to troubleshoot the public folder replication issue:

http://support.microsoft.com/?id=842273

If the problem persists after performing the steps given in the above article, turn on the diagnostic logging on both the Exchange servers and check for event ids in the application log and proceed accordingly with further troubleshooting steps. The above article mention on how to turn the diagnostic logging for public folder replication.
Articles for Reference:
TechNet Support WebCast: Troubleshooting public folder replication:
http://support.microsoft.com/?id=907304

How to Send Replication Status Request Messages in Exchange 2000 Server:

http://support.microsoft.com/?id=321082

Replication does not occur for one Exchange server in the organization:

http://support.microsoft.com/?id=812294

Public Folder Hierarchy and Content Is Not Being Replicated Across Routing Groups:

http://support.microsoft.com/?id=260330

Description of the public folder referral functionality in Exchange 2000 Server and in Exchange Server 2003:

http://support.microsoft.com/?id=273479

Public Folder Replication Troubleshooting:

http://www.microsoft.com/technet/prodtechnol/exchange/guides/WorkingE2k3Store/f92870f5-ad69-4b45-96cd-4a32a03537a7.mspx

Controlling Exchange Server 2003 Public Folder Replication:

http://www.microsoft.com/technet/prodtechnol/exchange/guides/WorkingE2k3Store/f92870f5-ad69-4b45-96cd-4a32a03537a7.mspx

=========================================================================
Issue 6:

Problem Expanding Public Folder Hierarchy from the Exchange System Manager.

Possible causes:

 Incorrect IIS settings.

 IIS database is corrupted.

 IIS lockdown tool is installed.

 Anti virus scanning the Exchange databases in the background.

Solution:

 Check for the event ids in the application log.

The errors are separated by graphical images of the actual error themselves, the associated possible causes and the troubleshooting steps to follow.

Error 80040e19

Possible Causes

• Improper IP address binding in IIS

• Host Header for the default web site is incorrect in IIS

• Incorrect Path name listed in IIS under the Home Directory tab

• Metabase can be corrupted

• URLScan may be installed on IIS blocking specific extensions or verbs

• Non working public folder store is selected in ESM

• Invalid folderpathname set for the http public folder in Active Directory.

• Other 3rd party ISAPI filters installed in IIS

• This can occur if the public folder hierarchy on the exchange server is associated with the public folder store with another server.

Troubleshooting

• Verify proper IP address, host header and port in the properties of the Default Web Site. IP address by default is set to all unassigned with no host header bound to port 80. Set back to defaults for testing purposes. If multiple IP addresses are bound to the network card due to the “All in one” syndrome with running multiple websites on an exchange server, try using the first bound IP address. Add host header if necessary to get around this. Change port if necessary. If this error is occurring on a cluster server, then you may need to add a host header for the Exchange cluster virtual name to the website to get this working

• Check to make sure that URLScan is not installed on the server. This can be found by getting the master WWW properties in IIS and selecting the ISAPI filters tab. If URLScan is listed, then the best thing to do to see if URLScan is causing the problem is to check the urlscan.log file that is created in the \winnt\system32\inetsrv\urlscan folder.

http://support.microsoft.com/?id=328659

IIS lockdown and URLscan configurations in an Exchange environment:

http://support.microsoft.com/?id=309508

NOTE: Once a setting in the urlscan.ini is changed for use with URLScan, the IISAdmin service will need to be restarted for the change to take effect. Keep in mind that this will stop the Information Store which will affect Outlook and OWA clients.

• Connect to another Public Folder store, if available, to see if the issue persists. To do this, right click on “Public Folders” and then select “Connect to…” and then select another PF store.

• Check the properties in IIS on the public and exadmin folders whether they are pointing to the proper Home Directory paths. Be default, exadmin should point to \\.\BackOfficeStorage and public should point to m:\domain.com\public folders. Having incorrect directory paths will cause this issue even if it is off by one letter. For example, if Public Folders was spelled Public Folder.

• Verify the correct folderpathname is listed for the http public folder. See SOX031125700026 for more information.

• Take a netmon trace when the client is attempting to connect to the public folders in the ESM, this will tell you what is being returned from IIS. The client, in this case, would be an ESM on another computer besides the Exchange server itself so that we can see the proper network traffic.

Error 80070005

Possible Causes

• There are instances where you are prompted for your network password and after 3 tries, you may receive this Access Denied error. This usually occurs when HTTP keep-alives and not configured for the default website.

Troubleshooting

• Get properties of the Default website and then put a check box in the “Enable HTTP Keep- Alives”

Error 80070057

Possible Causes

• Anonymous only authentication is set for the exadmin virtual directory. This normally occurs if the DS2MB replication process if broken and an administrator changed the access permissions for this vdir to anonymous only.

Troubleshooting

Check off the box to enable Integrated Authentication and then find out why the DS2MB process is failing to replicate this information from Active Directory in to the Metabase.

Error 80072030

Possible Causes

• This can occur if you are attempting to propagate permissions in the ESM for a top level folder in a Mixed Mode organization in which you have no local Exchange 5.5 replicas on this server.

Troubleshooting

You Receive an Error Message When You Propagate Public Folder http://support.microsoft.com/?id=317675

Error 80090301

Possible Causes

• This can occur if you are requiring SSL for the exadmin virtual directory under the Default website, but there is no certificate bound to the website. • Incorrect Host header is configured for the Default Web Site.

Troubleshooting

• To resolve this, open the ISM and then get properties of the exadmin vdir and select the Directory Security tab. From there, select the Edit Button under Secure Communications. Uncheck “Require 128-bit encryption” and then uncheck “Require secure channel (SSL). Click OK and then expand Public Folders again.

• If you do not have access to change this information in the ISM, then you can manually remove this.

o Open a command prompt and then change in to the \inetpub\adminscripts folder.

o Run “cscript adsutil.vbs enum w3svc/1/root/exadmin” to view the settings for that virtual directory. You should see the following if you are experiencing this error.

AccessSSL : (BOOLEAN) True

AccessSSL128 : (BOOLEAN) True

To change this to not require SSL, perform the following command.

cscript adsutil.vbs set w3svc/1/root/exadmin/AccessSSL False

cscript adsutil.vbs set w3svc/1/root/exadmin/AccessSSL128 False

• Remove any incorrect host headers from the website.

Error c007274c

Possible Causes

• Incorrect Host Headers defined on clustered virtual server

Troubleshooting

• Add or remove the correct host headers to the Exchange VS in IIS.

Error c1030af0

Possible Causes

• This can occur if you have multiple IP addresses bound to the network card on the Exchange server and you have the default website bound to this secondary IP address.

• An invalid host header or IP address has been set for the default website

• Incorrect IP addresses or host header is set on the cluster virtual server.

Troubleshooting

• Try setting the default web site to “All Unassigned” and then reopen the ESM and try to expand Public Folders.

• Correct the host header value or remove it altogether.

Error c1030af1

Possible Causes

• You will see this error message if you go to the properties of the Default Website > select the Directory Security Tab, click the Edit button of IP address and domain name restrictions > and Deny your Exchange server’s IP address or subnet.

• Network card bindings are set incorrectly.

• Read access on the exadmin virtual directory is unchecked

Error c1030af2

Possible Causes

• Davex In-Process ISAPI application is not loaded or missing on the Master WWW properties.

• ExchangeApplicationPool has been deleted in IIS. See SOX040609700142 on how to recreate this.

• Default website is listening on a port other than port 80.

Troubleshooting

• Check the IIS logs to see if all http requests are connecting over port 80. If any other port is listed, then you will get this error.

• Use Metaedit or MBExplorer to add this information back. A Metaedit sample view is shown below. Once adding this back in, Public Folders should be able to expand immediately. The path to get to this is LM/W3SVC and then double-click on the InProcessIsapiApps to get the below view. Note: Davex is also explicitly set at the vdir level, but that is not used for administration, only the viewing of Public folders through OWA.

• If all else fails, try the following (Taken from SOX040413700052)

o Perform a backup of the IIS Metabase. Right-click the servername in IIS Manager, select All Tasks and then Backup/Restore.

o Remove the Exadmin virtual directory.

o Open up a command prompt and navigate to the following directory: C:\Inetpub\AdminScripts

o Run "cscript.exe adsutil delete ds2mb" (this deletes the ds2mb in the Metabase)

o Restart the Exchange System Attendant (this will restart the Information Store and the MTA Stacks and recreate the Exadmin virtual directory)

o Verify the Exadmin folder had been recreated in IIS Manager.

o Test to see if we are able to expand the public folder tree.

IIS logging properties reference –

http://www.microsoft.com/resources/documentation/WindowsServ/2003/standard/proddocs/enus/Default.asp?url=/resources/documentation/windowsserv/2003/standard/proddocs/en-us/ref_we_logging.asp

Error c1030af3

Possible Causes

• Improper authentication method set in IIS for the public and exadmin vdir’s

• DS2MB process has not populated the proper entries in the IIS metabase

• IE security settings are incorrect.

• Permissions in Active Directory are set incorrectly

• Realtime virus software is scanning the M: Drive

• The msExchDS2MBOptions for the exadmin virtual directory is set incorrectly.

• There is an incorrect path listed for the properties of the exadmin vdir in IIS. This value should be \\.\BackOfficeStorage.

Troubleshooting

• Ensure that a proper authentication method is selected for the HTTP Public Vdir in the ESM. If none is listed, then you will receive the above error. If the correct authentication method shows up in ESM, open the Internet Service Manager to see if the same authentication method is listed for the Public vdir. Also check the exadmin vdir for the same authentication method. If this authentication method is not present, then there is a problem with DS2MB replicating this information from Active Directory to the IIS metabase. Check the event log for additional information regarding the failing DS2MB process.

• Open the ESM on another computer or server. If this works, then this is machine specific.

• Set your IE security settings to a lower setting such as Med-Low.

• Check permissions on the Top level Public Folder using ADSIEdit or the ESM to ensure no specific denies are set. Correct if necessary.

• Exclude the M: Drive or hidden EXIFS mapping from any AV File level scanning. Restart server to release any locked or open files.

• If msExchDS2MBOptions is set to 0 for the exadmin vdir, the above error will occur. Reset this back to the default of 66 and allow time for replication to the metabase.

Error c1030af4

Possible Causes

• The exadmin vdir local path has a trailing backslash in the path such as the following \\.\BackOfficeStorage\

Troubleshooting

• Remove the trailing backslash for the vdir properties in IIS and then refresh the ESM.

Error c1030af6

The operation failed because of an HTTP error 501 (Not implemented). Verify that the ExAdmin virtual root exists on the destination server.

ID no: c1030af6 Exchange System Manager.

Possible Causes

• The cause of this is similar to c1030af7

Error c1030af7

Possible Causes

• This can occur if you have multiple Web sites configured and the default website is currently stopped. This website includes the associated vdirs (exadmin, exchange, public, exchweb) which are not available when that site is stopped.

• The exadmin vdir is missing within IIS

Troubleshooting

• Check to see if the exadmin directory exists in IIS under the default website. If it does not, from a command prompt in the \inetpub\adminscripts folder, enter “cscript adsutil.vbs delete ds2mb” and hit enter. This will remove the information from the metabase. Restart the System Attendant service to get this information repopulated in IIS.

Error c1030af8

The operation failed due to HTTP error 501 ID: c1030af8

Possible Causes

• This can occur there is another service taking up port 80.

Troubleshooting

• Run “fport.exe 80” to find the offending service and either disable it or change its port number.

Error c0072af9

Possible Causes

• You are unable to resolve the DNS name for the server you are trying to connect to in the ESM.

Troubleshooting

• Try pinging the server by both the netbios name and the FQDN name.

• If the servers name is not registered in DNS, go ahead and register it by opening a command prompt on the remote server and typing “ipconfig /registerdns”. Verify in the DNS manager that this was registered properly.

Error c1038a21

Possible Causes

• RUS is not stamping public folders with proxy addresses

• The Microsoft Exchange System Objects folder is not located in the root of the domain

• The folder in question is not mail enabled.

• The ExchangeApplicationPool has been deleted from IIS.

Error c0072afc

Possible Causes

• You are unable to resolve the DNS name for the server you are trying to connect to in the ESM.

Troubleshooting

• Try pinging the server by both the netbios name and the FQDN name.

• If the servers name is not registered in DNS, go ahead and register it by opening a command prompt on the remote server and typing “ipconfig /registerdns”. Verify in the DNS manager that this was registered properly.

Error c0072741

Possible Causes

This can occur if the msExchSecureBindings or msExchServerBindings attribute is populated with invalid information. For example: if port 443 is listed and there is not a SSL certificate bound to the default website.

Troubleshooting

To resolve the above issue, do the following.

• Go to Start - Programs - Windows 2000 Support Tools - Tools and launch ADSI Edit.

• In the left side pane expand the Configuration container.

• Next expand CN=Configuration

• Then CN=Services CN=Microsoft Exchange CN= CN=Administrative Groups CN=First Administrative Group CN=Servers CN=Protocols CN=HTTP CN=1

• Right Click on CN=Exadmin and choose Properties.

• In the Properties dialog box you will see 2 drop-down lists. drop down the top list and select "Both". Drop down the second list and scroll down to the attribute "msExchSecureBindings" and double click on it.

• If this attribute is set to 443 or any other value really, click the 443 value to select it and click the "Remove" button. Then click "Apply" and then "OK"

• Close out of ADSI Edit, close and reopen Exchange System Manager and test Public Folder access again.

Error c103b401

Possible Causes

• This can occur if the default website (Default) is not configured to use port 80 or an incorrect host header is configured.

• Default Website is stopped in IIS causing the exadmin vdir to be unavailable.

• Website is configured to use an external IP address, not internal.

• msExchServerBindings attribute in Active Directory for the exadmin container has an incorrect port number populated.

Troubleshooting

• Change the Default website to listen on port 80 and remove any host header entries.

• Start the Default Website on the Exchange server that you are attempting to connect to in the ESM.

• Try binding the website to “All Unassigned” or an internal IP address.

• Verify that msExchServerBindings port number for the exadmin vdir matches the port bound to the Default Web Site.

• Try connecting to another Exchange public folder to see if the same issue occurs on another server.

Error c103b404

Possible Causes

• This can occur if you have a certificate bound to the default website, you have required SSL on the exadmin virtual directory, and the certificate common name does not contain the FQDN of the server name that IIS is installed on.

Troubleshooting

• To resolve this issue, remove the certificate from the default website and request a new certificate that contains a common name of the FQDN of the server.

Error c103b405

Possible Causes

• The exadmin vdir local path is set to a value other than \\.\BackOfficeStorage

This can occur if the following are true.

o Multiple IP Addresses are bound to the NIC card

o Multiple websites are configured on the Exchange server

o The default website is bound to the secondary IP address that is bound to the NIC card

o No DNS mapping for the second IP that maps to the FQDN of the server

Enter Network Password

Possible Causes

• HTTP keep-alives and not configured for the default website.

Troubleshooting

• Get properties of the Default website and then put a check box in the “Enable HTTP Keep-Alives”

Articles for Reference:

Troubleshooting Microsoft Exchange System Manager Public Folder Expansion Problems:

http://www.microsoft.com/technet/prodtechnol/exchange/2003/insider/publicfolders.mspx

Please see the web version of this document (will also be the most updated one) here:

http://msweb/personal/mikelag/Shared%20Documents/ESM%20PF%20Troubleshooting/default.htm

=========================================================================

Issue 7:

Problem downloading Offline address book

====================================

Possible Causes

• Check for the Exchange server (Home server) responsible for generating the OAB.

• In the Default Offline Address List properties, confirm that the Default Global Address List is in the Address List list. Add any other address lists that are necessary for offline access. Check whether the replica’s are added for the OAB system folder.

• Check for the OAB system folders (OAB Version 2a for Exchange 2000 and Version 3a for Exchange 2003).

• Check for the public folder tree listed on public folder store.

• Compare the value of the Distinguish Name on the public folder store with the value of site folder server on the Administrative group using ADSIEDIT.

• If the mailbox store has not been associated with a valid offline Address Book.

• Check whether outlook is configured for Cached-Exchange mode.

Troubleshooting

=============

If the mailbox store has not been associated with a valid offline Address Book:

1. Start Exchange System Manager.

2. Expand Organization, and then expand Administrative Groups.

If "Administrative Groups" does not appear under Organization, make sure that you have configured Exchange System Manager to display Administrative Groups. To do so, right-click Organization, click Properties, and then click Display administrative groups.

3. Expand the administrative group to which the server belongs.

4. Expand Servers, expand the server that you want to configure, and then expand First Storage Group.

5. Right-click Mailbox Store, and then click Properties.

6. In the Offline Address Book section, make sure that a valid offline Address Book is listed.

If one is not listed, click Browse, and then click a valid offline Address Book. You can use Default Offline Address Book as the default setting.

Replicate the Offline Address List to Other Servers

If there are multiple sites in the Exchange organization, replicate the default offline address list to the servers in those sites to improve download performance. To replicate the offline address list to other servers:

1. Open the properties of the OAB Version2 object, and then click the Replication tab.

2. Add the other servers to the Replicate content to these public stores list.

3. Click OK to save the changes.

4. The replication of the OAB Version2 folder follows the replication schedule of the public folder store by default. To force replication to occur immediately, rebuild the default offline address list.

Enable Diagnostics Logging

To troubleshoot activity that occurs when the offline address list is rebuilt, increase the diagnostic logging to maximum on the following object in the offline address list server properties:

Service: MSExchangeSA

Category: OAL Generator

To turn the diagnostic logging, follow the below steps:

Open the ESM -> Right click on the Exchange server name -> properties -> diagnostic logging tab

Monitor the Application event log for events that can assist you in troubleshooting issues with offline address list generation.

Rebuild the Offline Address List

If the OAB Version2 folder is missing from the Public Folders container (to locate this container, click the Administrative Groups container, click the Servers container, click the server_name container, and then click the First Storage Group container), rebuild the default offline address list in Exchange System Manager. To rebuild the default offline address list:

1. Expand the Recipients container, and then expand the Offline Address Lists container. Delete and re-create the Default Offline Address List by using a different name.

Note: If you do not use a different name, you will not be able to download the offline address list.

2. Open the Default Offline Address List properties, and then set the Update Interval to Always.

3. In the Default Offline Address List properties, confirm that the Default Global Address List is in the Address List list. Add any other address lists that are necessary for offline access.

4. Click OK to save the settings.

5. Right-click the Default Offline Address List, and then click Rebuild. Allow time for the system to rebuild the offline address list and replicate the information among the domain controllers.

6. Verify that the OAB Version2 folder was created successfully in the Public Folders container under the Administrative Groups\Servers\server_name\First Storage Group containers. If the OAB Version2 folder was not created, view the Application event log to determine which errors occurred.

7. If the OAB Version2 folder was successfully created, verify that a MAPI client can download the offline address list.

If the system folders (OAB version 2a or OAB version 3a) then we need to reset the system folders by following the steps listed in the below website:

http://support.microsoft.com/kb/275171/

Articles for Reference:
=================
TechNet Support WebCast: How to troubleshoot Offline Address Book issues in Microsoft Exchange Server: http://support.microsoft.com/kb/905482/en-us

How to Reset System Folders: http://support.microsoft.com/kb/275171/

=========================================================================
Issue 8:

Troubleshooting Recipient Update Service, RUS failed to stamp proxy addresses on User accounts.

Possible Causes:

• Incorrect Domain RUS settings i.e.: Not pointing to the correct servers.

• Missing permissions (Recipient Update Service does not have the necessary access permissions to update the objects)

Incorrect Domain RUS settings

We need to check whether the Domain RUS is pointing to the respective Exchange server and to the Domain Controller by viewing the properties page of the Domain RUS.

1) Click Start – Programs – Microsoft Exchange – System Manager

2) Expand Recipient container – Recipient Update Service

The following objects are displayed:

• Recipient Update Service (Enterprise Configuration)

• Recipient Update Service (Domain_name)

3) Right click the Domain RUS – Click properties.

The domain, the Exchange server, and the Windows domain controller that are involved in running this instance of the Recipient Update Service are displayed. The Update interval setting is also displayed. This is set to Always Run by default.

4) To change the Exchange computer on which an instance of the Recipient Update Service runs, click Browse next to Exchange computer, locate the Exchange server that you want the Recipient Update Service to run on, and then click OK.

5) To change the Windows domain controller that this instance of the Recipient Update Service connects to when it updates objects in Active Directory, click Browse next to Windows Domain Controller, locate the domain controller that you want the Recipient Update Service to connect to, and then click OK.

Important Points

• Each instance of the Recipient Update Service associates one Exchange server (where the Recipient Update Service runs) with one Windows 2000 or Windows Server 2003 domain controller (on which the Active Directory objects are updated). Only one Recipient Update Service object can be associated with one Active Directory domain controller.

• We can have multiple instances of the Recipient Update Service on an Exchange server, but each domain controller in a domain can only participate in one Recipient Update Service. If you want multiple Recipient Update Services for a domain, that domain must have more than one domain controller.

• Creating a RUS, the Exchange server is granted rights to modify Exchange Server attributes on recipients that are in the domain.

• When you are creating a Recipient Update Service, you cannot select the domain controller. You can only select the domain that you want the new Recipient Update Service to be associated with. After you have finished creating the Recipient Update Service, you can edit the properties of the Recipient Update Service and select the domain controller that you want. (Vimp)

UPDATE and REBUILD
==================
• If you perform an update operation, proxy e-mail addresses are generated immediately for all new users. This operation forces address book membership to be recalculated for recently modified Exchange recipients. Perform an update operation if you are running the Recipient Update Service on a schedule and you want to complete mailbox creation before the next duty cycle runs.(UPDATE)

• • If you perform a rebuild operation, all proxy e-mail addresses are recalculated and all address list memberships are verified. Perform a rebuild operation if you make a change to organizational policy on SMTP addressing (for example, if you change the DNS domain suffix from .com to .net or if you change the DNS domain name). A rebuild operation may take several hours. We recommend that you perform this operation during a period of low network activity. (REBUILD)

Missing Permissions

Four possible reasons for this behavior:

• Administrator or user of built-in Active Directory security group name or log on does not resolve.

• Inheritable permissions from parent are not propagated to object check box on the Active Directory organizational unit that the accounts reside in.

• Exchange Enterprise Servers group is missing required permissions at the domain level.

• Group has the hideDLMembership attribute set to True. (KB253828)

SOL: To resolve the permissions issue, run DomainPrep on the Domain controller or on the Exchange server.

:\I386\Setup.exe /domainprep

For detailed information on required permissions for RUS, Visit the following web site:

http://support.microsoft.com/kb/254030/

=========================================================================
Issue: 9

Troubleshooting Virtual Defragmentation Problems

Possible Causes:

• Exchange server is running on low virtual memory.

• Anti virus may reduce the virtual memory to a level below the 32 MB address space. (Where an antivirus program that is configured to scan the messaging databases reduces the virtual memory block to less than 32 MB).

Note: Event ID 9582 or 12800(Performance issues) in the application log indicates the problem of Virtual Defragmentation. When you scale a server to handle more users and larger loads, the server may run low on virtual memory in the Microsoft Exchange Information Store process (Store.exe). When this issue occurs, event ID 9582 events are logged to the application event log. You can use a monitoring tool that generates an administrative alert each time an event ID 9582 message is logged.

When an Exchange server has less than 32 MB of free contiguous virtual

address space, the following warning message is logged to the application event log:

Source: MSExchangeIS

Category: Performance

ID: 9582

Type: Warning

Description:

The virtual memory necessary to run your Exchange server is fragmented in such a way that performance may be affected. It is highly recommended that you restart all Exchange services to correct this issue.

For more information, click http://search.support.microsoft.com/search/?adv=1

When this warning message is logged, follow these steps:

1. Prepare and perform the steps to shut down and then restart the server in the next 36 to 72 hours.

2. To determine the rate of decay, use the Performance Logs and Alerts tool to monitor the following counter for the MSExchangeIS performance object :

• VM Total Large Free Block Bytes

Use this data to help you plan an appropriate time (in the next 36 to 72 hours) to shut down and then restart the server.

When an Exchange server has less than 16 MB of free contiguous virtual address space, the following error message is logged to the application event log:

Source: MSExchangeIS

Category: Performance

ID: 9582

Type: Error

Description:

The virtual memory necessary to run your Exchange server is fragmented in such a way that performance may be affected. It is highly recommended that you restart all Exchange services to correct this issue.

For more information, click

At this level of virtual memory fragmentation, the Store.exe process cannot create additional heaps and cannot correctly mount and dismount storage groups. If the VM Largest Block Size counter is below 10 MB, the storage groups do not mount. When an event ID 9582 error message is logged, prepare to shut down and restart the server. When you shut down and then restart the server to clear virtual memory fragmentation, there are additional considerations when Exchange 2000 Server is configured in a clustered environment. When you move cluster resources from one node to another node, this process does not ensure a "clean" virtual memory address space. If cluster resources are owned by the destination cluster node, and the cluster resources are moved to the passive node (without first restarting the destination node), you may experience virtual memory fragmentation on the passive node. To avoid this situation, and to clear memory fragmentation in an Exchange 2000 Server clustered environment, follow these steps:

1. Restart the passive node before you move cluster resources to it.

This step helps to make sure that the cluster resources are moved to a server that has a "clean" virtual memory address space.

2. Move the cluster resources to the passive node.

3. Restart the node that previously owned the cluster resources.

Note: Exchange Server 2003 restarts the Store.exe service automatically after the resource records have been moved to a different node in the cluster to reset the Store.exe address space on that node. Therefore, the next time that the Exchange virtual server is moved back to the passive node, the Store.exe is operating with a "clean" address space.

Event ID: 9665 Warning messages

Exchange 2003 performs an optimal memory configuration check when the Store.exe process starts. If the memory settings are not optimal, an event ID 9665 warning message is logged to the application event log of Event Viewer. This warning message is logged when any one of the following conditions is true:

• Exchange is installed on a computer that is running any version of Microsoft Windows 2000 Server, and the SystemPages value in the registry is set outside the range of 24000 to 31000.

• Exchange is installed on a computer that is running Microsoft Windows 2000 Advanced Server or Microsoft Windows 2000 Datacenter Server, and the server has 1 gigabyte (GB) or more of physical memory (RAM) installed but does not have the /3GB switch set in the Boot.ini file.

• Exchange is installed on a computer that is running Microsoft Windows Server 2003 Standard Edition, Microsoft Windows Server 2003 Enterprise Edition, or Microsoft Windows Server 2003 Datacenter Edition, and the SystemPages value in the registry is set to a value other than 0.

• Exchange is installed on a computer that is running Windows Server 2003 Standard Edition, Windows Server 2003 Enterprise Edition, or Windows Server 2003 Datacenter Edition, the server has 1 GB or more of RAM installed, and the /3GB switch is set, but the /userva switch is either not present in the Boot.ini file or is set outside the range of 3030 to 2970.

• Exchange is installed on a computer that is running any version of Windows 2000 Server or Windows Server 2003, and the HeapDeCommitFreeBlockThreshold value in the registry is set to a value other than 0x00040000.

When an event ID 9665 warning message is logged, follow these steps

1. Check the SystemPages setting and the HeapDeCommitFreeBlockThreshold setting in the registry.

2. Check the /3GB switch and the /userva switch in the Boot.ini file.

ote: If you want to turn off the memory configuration check, add the Suppress Memory Configuration Notification DWORD value to the following registry key, and then set the value to 1:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeIS\ParametersSystem

The following counter is the most important counter to monitor for virtual memory fragmentation in the Store.exe process in Exchange 2003 and Exchange 2000:

Performance object: MSExchangeIS

Counter: VM Largest Block Size

This counter displays the size (in bytes) of the largest free block of virtual memory. This counter appears as a line that slopes downward as virtual memory is used. If this counter drops below 32 MB, Exchange logs an event ID 9582 warning message in the application event log. If this counter drops below 16 MB, Exchange logs an event ID 9582 error message in the application event log. If the largest free block is small (less than 10 MB), the server is approaching a critical state where message operations may start to fail and event ID 12800 error messages are repeatedly logged. (Refer to the web site to add more counters for monitoring the VM issues: http://support.microsoft.com/kb/296073/)

Setting /3GB switch:

Important points:

• Windows 2000 server does not support /3GB switch.

• Adding /3GB switch increases the Virtual Address Space.

• One of the effects of using the /3GB switch is a significant reduction in the number of system pages that are available to the kernel. Setting the /3GB switch in the Boot.ini file on Exchange servers is to modify the default settings and to increase the number of system pages that are allocated.

• When you set the /3GB in the Boot.ini file on a Windows Server 2003-based computer, set the /userva switch in the Boot.ini file to a value between 2970 and 3030. The recommended value is 3030 (this value is the equivalent to the Windows 2000 SystemPages value of 31000).

On Windows 2003, the /userva switch is to be used instead of the SystemPages registry key. They should not be used in conjunction. If the value for the /userva switch is not set between 2970 and 3030 in the SystemPages registry entry, and the /3GB switch is set, Exchange 2003 logs Event ID 9665 to the application event log. This event ID indicates that virtual memory on the server is not configured to use the optimal memory settings.

To set the SystemPages registry value on a computer that is running Windows 2000 Server, follow these steps:

1. Click Start, and then click Run.

2. In the Open box, type regedit, and then click OK.

3. Locate and then click the following registry key:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management

4. In the right pane, double-click SystemPages.

5. In the Value data box, type a value between 24000 and 31000, and then click OK.

6. Quit Registry Editor.

For more information on the above registry key, refer to the below web site:

http://support.microsoft.com/?kbid=325044

Setting HeapDeCommitFreeBlockThreshold registry value:

The HeapDeCommitFreeBlockThreshold registry value is the minimum size of a free block that the heap decommits. The default setting is 0 (zero). This means that the heap manager decommits each 4 KB page that becomes available. Decommit operations can cause additional virtual memory fragmentation. You can set the HeapDeCommitFreeBlockThreshold registry entry in the following registry key to a higher value to help reduce virtual memory fragmentation:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager

The recommended value to use for the HeapDeCommitFreeBlockThreshold registry entry is 0x00040000

For more information on the above registry key, visit the below web site:

http://support.microsoft.com/kb/315407/

Note: The HeapDeCommitFreeBlockThreshold registry entry is independent of the /3GB switch.

Articles to Refer:

How to troubleshoot virtual memory fragmentation in Exchange Server 2003 and Exchange 2000 Server:

http://support.microsoft.com/?kbid=325044

A description of the 4 GB RAM Tuning feature and the Physical Address Extension switch:

http://support.microsoft.com/kb/291988/

Exchange 2000 requires /3GB switch with more than 1 gigabyte of physical RAM

http://support.microsoft.com/kb/266096/

The "HeapDecommitFreeBlockThreshold" registry key

http://support.microsoft.com/kb/315407/

How to modify the Store Database maximum cache size in Exchange 2000 Server:

http://support.microsoft.com/kb/266768/

Monitoring for Exchange 2000 memory fragmentation:

http://support.microsoft.com/kb/296073/

Virtual Memory Fragmentation Occurs When You Fail Over an Exchange 2000 Virtual Server:

http://support.microsoft.com/kb/810985/

=========================================================================
Issue 10:

Error message “Mailboxes still exist in the mailbox store” while removing the Exchange server from the site or organization.

Solution:

By default we have three mail boxes listed in the mail box store when we install the Exchange server.

• SMTP mail box. (when PF replication happens through mail that time SMTP mailbox uses)

• System mail box. (it uses for system generated mail reports or NDR )

• System Attendant mail box. (It’s only one for each exchange server, when user access mail through OWA and create appointment it uses SA mailbox to publish system site folder.)

To check whether we have any other mail boxes in the mail box store we need to verify an attribute “MSExch HomeMDBBL or HomeMDBBL” on the mail box store using ADSIEDIT in the Active directory. We need to install the Windows support tools to open ADSIEDIT console.

Expand configuration container -> services -> Microsoft Exchange -> Organization name -> Administrative groups -> Administrative Group name -> First storage group -> Information store -> Mail box store -> Properties.

Look for the above attribute. If found any mail boxes, search for the users in the AD and delete the mail boxes for the users or move the mail boxes to the other Exchange server in the site or organization.
=========================================================================
Issue 11:

Changing the database paths and log file path locations to the different drive from Active directory. We can also change the paths from ESM.

Solution:

Open Adsiedit.msc from Run command.

We need to change the value for the following attributes:

MSEXCHEDB file on the mail box store for (.EDB files)

MSEXCHSLV file on the mail box store for (.STM files)

MSEXCHLogfilePath on the storage group for (Log files location)

Note : We need to dismount the stores before changing the paths.

How to Move Exchange Databases and Logs in Exchange 2000 Server 257184

How to move Exchange databases and logs in Exchange Server 2003 821915

=========================================================================
Issue 12:

Understand -1018, -1019 and -1022 database errors in the application log.

Possible causes:

 If the databases get corrupted.

 Due to hardware failures.

 Check for any event id’s in the application and system logs and view the

Description of the event. If the event description indicates and hardware

Failures then we need to fix the issues with the hardware.

 If the issue is not with the hardware then restore the databases from the backup media. If the backup is not available then perform the hard repair on the databases followed by offline defragmentation and isinteg to fix the physical and logical corruptions in the database.

Understanding and analyzing -1018, -1019, and -1022 Exchange database errors:

http://support.microsoft.com/?id=314917

Group-Interview

2011-02-27T02:51:00.000-08:00

We know that an interview is a one-on-one discussion, and the Group Discussion is many-on-many discussion. If the many-on-many discussion is not managed to make it one-on-many, the results are less than stellar. Sometimes the group discussion is moderated (for example, in news programs on television) and sometimes it is not moderated (for example, in jury deliberations, in class team projects).

The advantage of a moderated group discussion is that the participant knows what to talk about and when to talk about it - obviously, when prompted by the moderator. The challenge to the participant is to know the subject matter thoroughly and be articulate in responding to questions and arguments. One must become a good listener and be able to support or rebut the arguments from others in the group. Thus, preparation for the participant involves learning the subject matter, anticipating as many questions and arguments as possible. Acquiring content knowledge is a necessary step but not a sufficient step. You have to practice applying the knowledge to various real and imaginary situations/scenarios. It is the combination of acquisition and application of knowledge that is paramount.

Group discussions, that are not moderated, pose additional challenges. In additional to subject knowledge, one also has to be careful about what to say and when to say it. In such a discussion, just as in jury deliberations, a quasi-leader (that is, moderator) often emerges as the discussion progresses. So what are the appropriate rules of engagement in a group discussion? Since only one person may emerge as the group leader, and that too only after the discussion progresses, here are some guidelines that may be helpful to all participants.

Guidelines for Non-Moderated Group Discussions

1. Stay focused on the topic. You share the responsibility to make the group as productive as possible. Do not go off on tangents, and if someone else does, try to bring the discussion back on track.

2. Talk only when you have something useful to say. Avoid the waste of "air time." Just because one talks a lot does not mean one contributes a lot. Strike a careful balance between the quantity and quality of talk. Your speaking contribution should either move the discussion forward or change the direction of the discussion.

3. Listen, Listen Listen. Do not get caught up with what great things you can say. Recognize other people's contribution, before you expect them to recognize yours. Continuity of discussion, and thus progress, can be achieved only when participants "build on" other's contributions. It does not mean you have to accept what others say - challenge that by all means, if necessary - but listen first.

4. One at a time, please! Only one person should talk at any time, while all others listen carefully.

5. No side meetings. Do not talk to others, outloud or whispering softly, when someone is talking to the group. If you have questions or comments, ask the group.

6. Be polite, yet confident. No matter how right you think you are, others' ideas at least deserve due consideration. Never utter phrases such as: "You are wrong!" "That is so stupid!" "Dumbest thing I have ever heard!" - even when you are 100% sure. Present an alternative way of looking at the situation and let the group support the right path forward.

7. Strive to become the group leader, BUT within reason. Sure, being unofficially recognized by your peers in the group shows your leadership qualities. Only one person can become that. Typically, the group consensus emerges over time. One does not need to be labeled a leader explicitly to acquire and discharge the expected role. Most often, the group, through its behavior, implicitly grants the role without verbally articulating it.

8. Leader, DON'T push it. Remember, the group had elected you, whether implicitly or explicitly, the leader/moderator. The group expects you to be fair to all participants while making progress. Give everybody a fair chance to speak. Do not let anyone dominate the air time. Draw out people who are quiet. Make it a dynamic group.

Since you would be in an assessment environment, you will be observed for not only what you contribute but also on how and when you contribute.

One more item. Group discussions are typically on a topic or on a scenario. You may not know the topic or scenario until the discussion is actually set to begin. Acquire content knowledge for all potential areas. As mentioned early, it the application of the acquired knowledge that would prove useful. Practice, Practice, Practice

Tips on interviews and Group Discussions

1. In a group discussion what should my objectives be and how should I achieve them?
2. Is it wise to take a strong stand either in favour or against the topic right at the start of a Group Discussion ?
3. Is it a good strategy to try and be the first speaker on the topic in a GD?
4. In an interview how does one handle the question "Tell us about yourself?".
5. Is it better to have a longer selection interview or a shorter one?
6. In the MBA entrance interview how do I justify my decision to pursue the MBA programme?

In a group discussion what should my objectives be and how should I achieve them?
In order to succeed at any unstructured group discussion, you must define what your objective in the group is. A good definition of your objective is - to be seen to have contributed meaningfully in an attempt to achieve the right consensus.

The key words in this definition are 'seen', 'meaningfully', and 'attempt'. Let us understand what each of these imply in terms of action points :

The first implication is that merely making a meaningful contribution in an attempt to achieve consensus is not enough. You have to be seen by the evaluator to have made a meaningful contribution in an attempt to build the right consensus.

In other words you must ensure that you are heard by the group. If the group hears you so will the evaluator. You must get at least some airtime. If you are not a very assertive person you will have to simply learn to be assertive for those 15 minutes. If you get cowed down easily in an aggressive group, you can say goodbye to the business school admission.

Many GD participants often complain that they did not get a chance to speak. The fact of the matter is that in no GD do you get a chance to speak. You have to make your chances.

The second important implication is that making just any sort of contribution is not enough. Your contribution has to be meaningful.

A meaningful contribution suggests that you have a good knowledge base, are able to structure arguments logically and are a good communicator. These are qualities that are desired by all evaluators.

Many GD participants feel that the way to succeed in a GD is by speaking frequently, for a long time and loudly. This is not true. The quality of what you say is more important than the quantity. Don't be demoralized if you feel you have not spoken enough. If you have spoken sense and have been heard, even if only for a short time, it is usually good enough. You must have substance in your arguments. Therefore, think things through carefully.

Always enter the room with a piece of paper and a pen. In the first two minutes jot down as many ideas as you can. It pays to think laterally. Everybody else will state the obvious. Can you state something different? Can you take the group ahead if it is stuck at one point? Can you take it in a fresh and more relevant direction? You may like to dissect the topic and go into the underlying causes or into the results.

One way of deciding what sort of contribution is meaningful at what point of time is to follow two simple rules. First, in times of chaos a person who restores order to the group is appreciated. Your level of participation in a fish market kind of scenario can be low, but your degree of influence must never be low. In other words you must make positive contributions every time you speak and not speak for the sake of speaking. The second rule is applicable when the group is floundering. In this situation a person who provides a fresh direction to the group is given credit.

The third implication is that you must be clearly seen to be attempting to build a consensus. Nobody expects a group of ten people, all with different points of view on a controversial subject to actually achieve a consensus. But did you make the attempt to build a consensus?

The reason why an attempt to build a consensus is important is because in most work situations you will have to work with people in a team, accept joint responsibilities and take decisions as a group. You must demonstrate the fact that you are capable and inclined to work as part of a team.

What are the ways that you can try to build consensus?

First, you must not just talk, you should also listen. You must realize that other people also may have valid points to make. You should not only try to persuade other people to your point of view, but also come across as a person who has an open mind and appreciates the valid points of others.

You must try and resolve contradictions and arguments of others in the group. You must synthesize arguments and try and achieve a unified position in the group. Try to think of the various arguments of your's and others' as parts of a jigsaw puzzle or as building blocks of a larger argument for or against the topic.

Try and lay down the boundaries or the area of the discussion at the beginning. Discuss what the group should discuss before actually beginning your discussion. This will at least ensure that everyone is talking about the same thing.

Try and summarize the discussion at the end. In the summary do not merely restate your point of view; also accommodate dissenting viewpoints. If the group did not reach a consensus, say so in your summary.

You must carry people with you. So do not get emotional, shout, invade other people's private space. Do not bang your fist on the table except in extreme circumstances.

If you have spoken and you notice that someone else has tried to enter the discussion on a number of occasions and has not had the chance to do so maybe you could give him a chance the next time he tries. But do not offer a chance to anyone who is not trying to speak. He may not have anything to say at that point and you will just end up looking foolish.

The surest way of antagonizing others in the GD as well as the examiner is to appoint yourself as a de facto chairperson of the group. Do not try to impose a system whereby everyone gets a chance to speak in turn. A GD is meant to be a free flowing discussion. Let it proceed naturally. Do not ever try to take a vote on the topic. A vote is no substitute for discussion.

Do not address only one or two persons when speaking. Maintain eye contact with as many members of the group as possible. This will involve others in what you are saying and increase your chances of carrying them with you. Do this even if you are answering a specific point raised by one person.

One last point. You must not agree with another participant in the group merely for the sake of achieving consensus. If you disagree, say so. You are not there to attempt to build just any consensus. You have to attempt to build the right consensus.

Is it wise to take a strong stand either in favour or against the topic right at the start of a Group Discussion ?

In theory yes. If you believe something why shouldn't you say so? If we are convinced about something our natural response is to say so emphatically.

However in practice what is likely to happen if you take a very strong and dogged stance right at the beginning of the interview is that you will antagonise the people in the group who disagree with you and will be unable to carry them with you and convince them of the validity of your argument. We therefore recommend that after you hear the topic you think about it for a minute with an open mind and note down the major issues that come to your mind. Don't jump to any conclusions. Instead arrive at a stand in your own mind after examining all the issues in a balanced manner. Only then begin to speak. And when you do so outline the major issues first and only then state your stand. In other words give the justification first and the stand later. If you were to state your stand first chances are that the others in the group who disagree with your stand will interrupt to contradict you before you can elaborate on the reasons why you have taken that stance. In this situation the evaluator will only get an impression of what you think and not how you think. Remember you are being evaluated on how you think and not what you think.

Is it a good strategy to try and be the first speaker on the topic in a GD?

In most GD's the opening speaker is the person who is likely to get the maximum uninterrupted airtime. The reason is simple - at the start most other participants in the GD are still trying to understand the basic issues in the topic, or are too nervous to speak and are waiting for someone else to start. Therefore the evaluators get the best chance to observe the opening speaker. Now this is a double edged sword. If the opening speaker talks sense naturally he will get credit because he opened and took the group in the right direction. If on the other hand the first speaker doesn't have too much sense to say, he will attract the undivided attention of the evaluators to his shortcomings. He will be marked as a person who speaks without thinking merely for the sake of speaking. As someone who leads the group in the wrong direction and does not make a positive contribution to the group.

So remember speaking first is a high risk high return strategy. It can make or mar your GD performance depending how you handle it. Speak first only if you have something sensible to say. Otherwise keep shut and let someone else start.

In an interview how does one handle the question "Tell us about yourself?".

An often asked opening question. Perhaps the most frequently asked question across interviews. Your opening statement needs to be a summary of your goals, overall professional capabilities, achievements, background (educational and family), strengths, professional objectives and anything about your personality that is relevant and interesting. This question represents an opportunity to lead the interviewer in the direction you want him to go e.g., your speciality or whatever else you may wish to highlight.

Your intention should be to try to subtly convince the interviewers that you are a good candidate, you have proved that in the past, and have a personality that fits the requirement.

Remember that the first impression you create will go a long way in the ultimate selection. Keep in mind, most candidates who are asked this question just blurt out their schooling, college, marks and qualifications. All this is already there in the CV. Why tell the interviewer something he already knows?

A final word on approaching this question. Once you have said what you have to say - shut up. Don't drone on for the sake of speaking for you just might say something foolish. Sometimes interviewers don't interrupt in order to give the candidate the impression that he has not spoken enough. This is just a stress inducing tactic. Don't fall for it, if you feel you have spoken enough. In case the pause gets too awkward for you just add something like, "Is there something specific that you wish to know about me?"

Is it better to have a longer selection interview or a shorter one?

The length of an interview in no way is an indicator of how well an interview went. This is especially so when there are a number of candidates to be interviewed for example in the civil services interview or the MBA entrance interview. In the past a number of candidates have reported varying lengths of interviews. Nothing positive or negative should be read into this. An interview is only a device whereby the panel seeks information about the candidate. Information that will help the panel decide whether or not the candidate should be selected. If the panel feels that it has gathered enough information about the candidate in 15 minutes of the interview commencing and that it has no further questions to ask the interview will be terminated in 15 minutes. If on the other hand the panel takes an hour to gather the information required to take a decision the interview will last for an hour. In either case the decision could be positive or negative. It is a fallacy to believe that interview panels take longer interviews of candidates whom they are more interested in. No panel likes to waste its time. If an interview is lasting longer than usual then it only means that the panel is seeking more information about the candidate in order to take a decision.

In the MBA entrance interview how do I justify my decision to pursue the MBA programme?

When you are asked this for God's sake don't tell the panel that you are looking for a "challenging job in a good firm with lots of money, status and glamour". That is the first answer that most candidates think of. Unfortunately it is the last answer that will get you admission. In the answer to a direct question on this subject you must convey to the interview panel that you have made a rational and informed decision about your career choice and your intended course of higher study. There are broadly six areas which your answer could touch upon :

Career Objectives : You could talk about your career objectives and how the two year MBA programme will help you achieve them. This implies that you have a clear idea of what your career objectives are and how you wish to achieve them. For example you may want to be an entrepreneur and wish to set up your independent enterprise after doing your MBA and then working for a few years in a professionally managed company. You could explain to the panel that the MBA programme will provide you with the necessary inputs to help you run your business enterprise better. But then you must be clear about what the inputs you will receive in the MBA programme are.

Value Addition : That brings us to the second area that your answer should touch upon. What is the value you will add to yourself during your two year study of management. Value addition will essentially be in two forms knowledge and skills. Knowledge of the various areas of management e.g. marketing, finance, systems, HRD etc. and skills of analysis and communication. You will find it useful to talk to a few people who are either doing their MBA or have already done it. They will be able to give you a more detailed idea of what they gained from their MBA.

Background : Remember, there must be no inconsistency between your proposed study of management and your past subject of study or your past work experience. If you have studied commerce in college then management is a natural course of higher studies. If you are an engineer this is a tricky area. You must never say that by pursuing a career in management you will be wasting your engineering degree. Try and say that the MBA course and your engineering degree will help you do your job better in the company that you will join. But then you should be able to justify how your engineering qualification will help.

Opportunities and Rewards : You could also at this stage mention the opportunities that are opening up in organizations for management graduates. Highlight with examples. At the end you may mention that while monetary rewards are not everything they are also important and MBAs do get paid well. You must not mention these reasons as your primary motivators even if that may be the case.

GD-Interviews

It is a discussion by a group of people. The discussion involves an exchange of thoughts and ideas among members of the group. Group Discussions are largely used in the selection process for admissions into institutes, where there is a high level of competition. The number of participants in a group can vary from 8-15 people. In most cases a topic or a situation will be given, and the group members will have to discuss it within a given period of time.

Reasons for employing a GD

• Value for time

GD helps in forming an opinion about a large number of candidates in a short period of time on a common platform.

• Skills assessment

GD helps in assessing certain skills that cannot be evaluated even in a personal interview (leave alone the written application form etc.). These skills include team membership, leadership skills, listening and articulation skills etc.

What is checked in a GD

All that one observes in a GD can be categorized into two broad areas: - The Content and the Process.

• The content is all about 'what' or the 'matter' spoken in the GD. Whereas, the process refers to the 'how', 'when' and 'why' of the GD.

• Both are equally important and need adequate attention at all stages.

• High quality contribution by one with no regard to the 'process' is as suicidal as another's contribution, which is high on packaging with little content.

Critical Success Factors in a GD

• Cognitive skills or knowledge

The most important aspect of your contribution to a GD is the Quality of Content (QOC), which is reflected in the points you speak and knowledge of the relevant subject you have, the supportive examples you give and data you generated etc.

• Comprehension of core idea

It is essential to deliver a high quality content. But to do that , you should speak on the topic and not deviate. It is checked whether you have identified the crux of the problem or not and whether the solutions you are offering is relevant to the problem or not.

• Logical reasoning

It includes understanding the topic, generating quality arguments, analysis and a progressive approach to a justifiable conclusion. This is one of the necessary attributes to be seen in an influential participant. Such people convey an impression of open minded and logic driven rather than that of an opinionated individual.

• Behavioural and Personality Skills

This includes certain attributes like rapport building, team membership, participation, patience, assertion and accommodation, amenability, leadership etc,. that are assessed during a GD.

• Communication Skills

You should be able to articulate your thoughts properly and you should also be able to understand what others are trying to tell you.

• Clarity of thought

In whatever you are articulating, are you following logical sequence/ order or is that you are presenting the points in some bits and pieces.

• Body Language and Eye Contact

These are some tools which check your level of confidence and whether you can work together effectively in group or not.

Types of Group Discussions

• Structured (or Default) GD

1. A structured GD is one that is most commonly used.

2. The group is given a topic for discussion with 10 to 20 minutes for discussion. The topic can be anything going under the sun.

3. There is no leader appointed for the group and the brief may or may not include anything but the topic for discussion. Here the topic of discussion is clearly defined and students know what is the objective of discussion.

• Unstructured GD

1. Unstructuredness can be built into a discussion wherein no clear instructions are given. So first of all, the students have to decide as to what is to be done.

2. The panel expects the group to achieve some objective(s) during the course or by the end of the GD, but here the objectives are to be decided by the group itself and not given by the observer.

These might include tasks such as choosing the topic for discussion, appointing the leader or a chairman etc.

The Interview

An interview is a face-to-face meeting, especially for the purpose of obtaining a statement or for assessing the qualities of a candidate.

An interview tries to obtain a statement or opinion, as is done for e.g. when film stars are interviewed to get their views on any particular role, or when the Prime Minister is interviewed to get statement on the result of his discussion with another political leader. So as a student going for interviews of management schools, we need to understand the various topics of general interest in details and should be able to discuss them intelligently.

Another purpose of the interview is to assess a person on various personal attributes like honesty, integrity, communication skills, ability to handle pressure, ability to plan for oneself, etc.

Must to do before an Interview

• Learn about the Institute

• Refresher on the subjects of you graduation or of general interest.

Tips for the Interview

1. Entering the room

o Prior to opening the door, adjust your attire so that it falls well.

o If the members of the interview board want to shake hands then offer a firm grip maintaining eye contact and a smile.

o Seek permission to sit down.

o Diffuse the tense situation with a light-hearted humour and immediately set a rapport with the interviewers.

2. Lead the Interview

o A good interviewee would be quick to settle and begin to lead the interviewers.

3. Enthusiasm

o The interviewer normally pays more attention if you display an enthusiasm in whatever you say.

o You should maintain a cheerful disposition throughout the interview i.e. a pleasant countenance holds the interviewers interest.

4. Be Brief

5. Don't Bluff - be honest

6. Humor- humor tends to break the monotony and puts every one at ease and also generates interest

and enthusiasm.

7. Interviewer fatigue

o Mostly interviews are conducted the whole day leading to fatigued minds.

o A little humour as a starter will ease the fatigued minds. However, if you do not have the knack of humour, it is better not to get into it.

o You must be proactive in offering information about yourself as the interviewers will be willing listeners.

8. Be well mannered: show courtesy

9. Avoid slang

10. Be poised

11. Ask Question, if necessary

12. Eye Contact- maintain good eye contact with the persons interviewing you.

13. Listen carefully and answer to the point.

14. Be natural, do not pretend that you are somebody else.

Preparing for tests, group discussions and interviews

Interviews usually consist of one or more of the following tests:

• Aptitude test

• Technical test

• Group discussion

• Psychological test

• Personal interview

• Technical interview

Some useful tips/checklists for each stage are given below.

Aptitude test

Most aptitude tests for software professionals check for quantitative, reasoning and verbal abilities. They will usually be multiple choice type question papers.

Reading up mathematics textbooks and dictionaries just before the test will not help much. These abilities are cultivated over a long period of time - most questions are based on what you studied in high school.

Practice tests can help a lot. Get hold of a few practice tests and do them 2-3 days before the actual test.

Don't panic on the day of the test - you will do your best if you are not worried. Aim at achieving as much as you did in the practice tests.

Try to finish as many questions as possible, if you are stuck on a difficult problem - leave it aside and proceed to the next one.

Technical test

Technical tests will examine your ability in your skill area. They would usually be for about 2 hours.

Tests will test your fundamentals in the skill area, some of the questions will be quite tricky. Try to get a good book in the subject area and refresh your fundamentals.

Practice tests can help a lot. Get hold of a few practice tests and do them 2-3 days before the actual test.

Don't panic on the day of the test - you will do your best if you are not worried. Aim at achieving as much as you did in the practice tests

Try to finish as many questions as possible, if you are stuck on a difficult problem - leave it aside and proceed to the next one.

Group discussion

Group discussions are meant to judge your communication and interpersonal abilities. The observers will be looking for verbal and non-verbal skills, clarity of thought, leadership abilities and other interpersonal skills. Usually a current topic will be taken up and a group of 8-12 people will be asked to discuss the topic.

There is no need to prepare on specific topics. If you read the newspapers - it should be enough.

You do not have to be the first to speak out to be noticed. It is often better for someone else to begin the discussion. However, if you are very well informed on the topic it might be a good idea to set the ball rolling.

Listen carefully to what others are saying. It is a good idea to quote others when you speak while supporting, building or even criticising them. Be natural and talk normally and be yourself - it always gives the best results.

Psychological test

Psychological tests are used to mainly determine your personal attributes. They will usually be multiple choice type question papers.

There are no right or wrong answers to psychological tests - it is your opinion!

Avoid trying to fool tests, they are usually designed to ask the same questions in different ways again and again. If you are manipulating, the results will show inconsistencies and the observer might choose to ignore the test or administer another test.

Personal interview

Personal interviews are usually conducted by Human Resources professionals. They will be trying to understand you as a person and your motivation for joining the company.

"Tell us something about yourself" is perhaps the most common first question asked in non-technical interviews. It might be a good idea to prepare a brief opening statement and be ready for the question. It will be a good idea to mention your education, jobs and interest in applying in your opening statement.

Interviewers will often have gone through your resume in detail, be prepared to explain any statement made in your resume.

Answer all questions directly and honestly, it is not a trial!

Don't try to mask all your weaknesses - all human beings have them and so does the person interviewing you.

"Why do you want to change a job" is another common question, be prepared for it. Honestly answer the question, if you are trying to get a better salary - say so. The lesser you conceal your motives - the easier it will be for the interviewer to make a decision. Keeping the interviewer in suspense will only lead to a postponement in decision - not a favourable decision.

Appearance is important - dress formally or as you will usually for an important occasion.
Appear at least 10 minutes before the interview. It makes a good impression and you also get some time to get used to the surroundings.

Technical interview

Technical interviews are usually conducted by a senior technical professional - usually the senior most in your functional area. It will aim at assessing your technical abilities.

Technical interviewers will often have gone through your resume in detail. They will ask you specific questions on the skills claimed by you and details of your projects.

If your claimed skills do not match your work experience - the interviewer will be confused and will ask you a question such as "Which area are you most confident in? ". Answer "Which area are you most confident in ?" honestly and back up by saying why you feel confident about it.

Sometimes the interviewer may not have had the time to go through your experience and skills and may still ask "Which area are you most confident in ?". In that case, draw his attention to the skill area mentioned which you are most proficient in and the most relevant project carried out by using that skill.

If you do not have the right answer to something -say so. No person knows everything ! You are expected to answer most of the questions - not all.

Usually, the technical interviewer will begin with simple questions and proceed to more complex ones. Be sure you get the first few right - otherwise the interview will get terminated very soon!

Technical and personal interviews may be carried out simultaneously by a panel. Try to speak more to the interviewer you are confident with - it will give you a support quarter in the panel.

There may be several round of interviews ending with the CEO of the company. The final interview will be to merely confirm your selection, however, sometimes the CEO may make an exception. Be prepared, don't be over confident.

GUIDE TO THE PREPARATION AND CONDUCT OF GROUP INTERVIEWS

Basic Principles

Advantages / Disavantages

Basic Rules and Conditions to Observe

• Selection of Participants

• Choosing a Moderator

• Structure

• Organization and Conduct of an Interview

• Key Elements of Moderation

BASIC PRINCIPLES

Group interview is an effective information collection technique if used with small groups. The more homogeneous the persons selected for a discussion group the more successful the exercise is likely to be.

CONTEXTS IN WHICH GROUP INTERVIEWS CAN BE USED

The group interview is one means of collecting information. It is very different from such forms of information collection as the questionnaire which we designed to identify opinion trends in a large population. The group interview is particularly useful in the following three circumstances:

1) in evaluation planning, in order to define the issues and identify key questions with as little room for doubt as possible;

2) when analyzing data collected by elaborate and sophisticated survey methods in order to confirm and further investigate the conclusions drawn from the analysis;

3) as a quick means of clarifying a situation or of getting more information in order to answer questions raised by decision-makers; it is therefore particularly useful in programme or activity planning.

Conferences and seminars bringing together large numbers of people with the same interests, occupation or skills are occasions on which the group interview technique can be used quickly and at relatively moderate cost.

When this technique is used for a sufficiently large number of small groups to constitute a representative sample of a given population, it may be considered that the information obtained is correct; caution should, however, be exercised before making generalizations from the conclusions drawn. In any case, one group alone should never be considered enough to cover one particular subject adequately.

ADVANTAGES DISADVANTAGES

• Quickly organized and implemented.

• Moderate cost in comparison with other in-depth survey techniques.

• More opinions, behavioural attitudes and feelings about particular subjects collected than by any other survey method.

• The information obtained is extremely precise and very detailed.

• Interactions and influences among the persons concerned by a specific programme or activity are revealed.

• Factors of agreement or disagreement are identified.

• The evaluator can analyze replies, explore particular subjects and bring out unsuspected facts; great flexibility in the way questions are asked. • Difficult to direct and control the discussion.

• Difficult to ensure homogeneity if there are several groups.

• The information obtained cannot really be generalized and is difficult to analyze.

• Highlights strongly biased and often contradictory opinions; a person with a strong personality can dominate the discussion.

• It is difficult to select persons and bring them together as a group in a place suitable for the interview.

Basic Rules and Conditions to Observe

If group interviews are to be effective and useful, several factors must be taken into account when they are being prepared and in progress. These factors must be combined to make the discussion as open as possible and produce as much information as possible on a given subject.

Selection of participants

The main factor in selecting the members of the discussion group is knowledge of a given subject. An attempt must also be made to form a homogeneous group in which differences such as social and economic level, age and sex will not make group members feel ill-at-ease and prevent them from concentrating on the topic. One may form several groups which are homogeneous as individual units but slightly heterogeneous in relation to each other. But as a rule one should try to select for group interviews people who have very much the same experience, knowledge and occupation.

Participants may be selected for a discussion group at random from a body of people such as participants in a conference, for example. The following criteria may be used to select the participants:

- knowledge of the field and subject to be discussed;

- homogeneity at the professional level;

- similar social and economic contexts;

- same age group; etc.

The number of participants must be small enough (minimum of four) to allow each person to speak, and big enough (maximum of ten) for a variety of opinions to be obtained.

There are three main stages in the process of selecting participants for a discussion group:

1) The first stage is to compile a list of persons who seem at first sight to meet the selection criteria.

The proportion of persons who really meet the selection criteria varies considerably depending on the fields covered by the discussion and the circles from which individuals are selected. In general, a basic list of about three times more than the number of people required should be drawn up. A list of conference participants is often a ready-made basis of selection as the event itself is a homogenizing factor.

2) The second stage is to get in touch with those persons to find out if they really are familiar with the topic and meet the criterion of homogeneity, and then if they would agree to participate in a discussion group.

This selection should preferably be done by telephone, systematically, using a contact sheet. It is complicated, difficult and very slow to contact and select people by mail, and interaction enabling decisions regarding the participation of each person contacted to be made quickly is impossible. Fax reduces the difficulties and delays and permits sufficiently rapid interaction, but remains nonetheless a difficult medium. If one wishes to take advantage of a conference, the participants may also be selected at the venue of the conference itself, while it is in progress; but this requires planning. It is therefore necessary to determine beforehand when and how the participants will be contacted during the conference (short questionnaire to be distributed, brief announcement during a plenary meeting, etc. ), the times when the interviews will be held, and the physical space required.

3) The third stage is to confirm the venue, date and time of the interview with those persons who have agreed to participate in a group discussion.

This confirmation is generally given in writing. In a conference setting, direct contact is important when inviting the persons selected. When possible, it may be very helpful to include the group interviews in the planning of the conference. That means getting in touch with potential participants, making a selection and informing the persons selected of the date and venue of the interviews well before the conference is held. This planning may even include budgetary provisions to allow the persons selected to extend their stay if the interviews are to be held outside the formal framework of the conference.

Example of a contact sheet used in contacting and selecting participants:
__________________________________________________________________

Particulars of person contacted:

Name:

Telephone N°:

Address:

Date:

Introduction of interviewer:

Hello, my name is...

I work at (organization or administrative division, etc. )

Presentation of the subject:

I am doing a survey on (e. g.: results obtained in technical and vocational

education projects implemented in countries x, y and z)

I should like to ask you a few questions. It will only take five minutes.

Selection: (Selection criteria may vary and may have been agreed according to the objectives of the evaluation)

1) Are you familiar with these projects?

O Yes (If yes, move on to question No 2)

O No (If no, end the conversation and thank the person)

2) Are you directly involved in the projects because of your job?

O Yes (If yes, move on to question No. 3)

O No (If no, end the conversation and thank the person)

3) How many years have you worked in this field? (criteria of age and expertise)

O 0 to 2 years (end the conversation and thank the person)

O 3 to 5 years (put in this category and move on to question No. 4)

O 6 to 10 years (put in this category and move on to question No. 4)

O 10 years or more (put in this category and move on to question No. 4)

4) What was your employment status for most of the time you have worked in this field (put in the appropriate category and move on to question No. 5)

O Self-employed professional

O Employed by a private firm

O Employed by a public body

Invitation to a group interview:

5) There is to be a discussion among specialists in your field on the usefulness of the results of the projects implemented and on factors that should be taken into consideration for future projects. That discussion is to be held at (venue) , on (date) . Would you be interested in taking part?

O Yes (move on to question No 6)

O No (end the conversation and thank the person)

6) I will send you written confirmation of the arrangements. Is your address (see address given at the top of the sheet)?

O Yes O No (write in the new address)

If you wish to have more information, you may call me at: (telephone number)

Thank you for your co-operation.

____________________________________________________________________

Choosing a Moderator

To conduct a group interview the moderator needs certain specific qualities which must be applied even-handedly. If the evaluator does not have such qualities, he or she should ideally give way to a qualified person and act as assistant. The moderator of a group interview must:

• have minimum knowledge of the field or subject discussed;

• be able to use common sense and logic;

• be imaginative as well as able to refer to a preconceived frame of reference;

• be lively while remaining very neutral;

• step in frequently, while being attentive to what others are saying;

• be capable of summing up without losing sight of shadings of opinion.

The Structure of an Interview

In preparing the questionnaire, composed of a maximum of ten key questions, for the interview, the rules followed in preparing any other type of survey questionnaire must be observed. If the group interview is intended to complement or confirm the findings of a survey by questionnaire, the questions must be formulated at two levels:

1) on the basis of the questions on the existing questionnaire;

2) by formulating new questions that are linked to the existing questionnaire but are based on the conclusions obtained.

If the group interview precedes a more exhaustive survey, it might be both helpful and time-saving to prepare questions for the group interview and the survey questionnaire in tandem.

The Organization and Conduct of the Interview

Particular attention must be paid to the need for the discussion to focus quickly on very specific aspects of the topic. Interview questions must start with general aspects but move on quickly to specific ones. The ‘opening’ question is usually very general, open and neutral, and must elicit a response from each participant in the interview. Example: ‘Do you think that the projects implemented in the field of technical and vocational education have helped the countries concerned to improve the skills of their labour force?’

Subsequent questions must make the discussion focus quickly on particular aspects. This is the severest test of the moderator’s skill, for while following the logical sequence of the questions prepared beforehand, he or she must focus the discussion while allowing the participants to express themselves clearly. The moderator’s main concerns are to get the discussion off the ground without making participants feel ill-at-ease and to interrupt the discussion without upsetting them. The moderator must establish himself or herself unmistakably as the leader of the discussion and must never abandon this role, even partly, to one of the participants. This is important, for if during an interview lasting three hours at most eight persons have to answer ten questions prepared beforehand, each person has only two minutes 25 seconds to answer each question. Ideally, the evaluator, if he or she is also the moderator, should be accompanied by someone to take notes or vice-versa. It is very difficult to conduct an interview in a lively way and at the same time write down the content of the discussions and also pay attention to the interplay of looks, tone and gestures, which all qualify the participants’ actual words, assist the moderator in directing the discussion and must be noted. It may be very useful to record the interview, but all the participants must agree to this, and the recording must be managed in such a way that it does not inhibit discussion. The moderator should always be able to stop the recording as he or she sees fit. That goes hand in hand with the need to make people feel at ease in each other’s company and to maintain an atmosphere of trust.

The physical environment can be very important in creating an atmosphere that encourages participants to exchange their views. Each participant must therefore be able to see the others and exchange looks easily. Here are examples of the seating arrangements usually used for group interviews.

Key Elements of Moderation

• Start the meeting with a very short word of welcome and by introducing the moderator and the assistant;

• go around the table for everyone to say who they are: this ‘making acquaintance’ is essential;

• state clearly and frankly the objective sought and the rules of the discussion;

• stress that everyone must say what they think, holding nothing back;

• start the discussion with a question that puts all the participants at ease;

• get the participants to discuss the substance of the topic as quickly as possible;

• bring each person into the discussion as quickly as possible;

• give all the participants equal speaking time;

• adapt the interview plan to developments in the discussion, taking care to keep sights on the objective and to focus discussion on the key topics;

• use a coffee break to ease the atmosphere, if necessary;

• accept all comments and replies in a neutral manner without having any reaction that would suggest that the moderator is biased one way or the other;

• avoid any form of verbal, visual or corporal reaction to the participants’ replies and comments;

• ask questions in a neutral and controlled tone of voice so as not to reveal any bias;

• make use of pauses in the discussion; someone will speak, after a few seconds;

• make use of comments by the ’leaders’ by interrupting them and encouraging other participants to react to them;

• use differences among the participants to bring out divergent opinions.

http://www.unesco.org/ios/eng/evaluation/tools/outil_05e.html

Eight Tips to Managing a Group Discussion

Many people become uneasy at the thought of leading a meeting or a group discussion. What if nobody talks? What if someone talks too much? Here are eight tips to guiding a fruitful discussion:

1. Watch who you watch. When someone else is talking, look at the other people in the room instead of at the speaker. This creates a feeling of greater inclusiveness.

2. Don't respond to every statement. Wait for others in the group to comments. If no one does, ask, "Are there any reactions to that?"

3. Keep control. If somebody talks too long, cut him or her off with: "I think I'm losing track of the point you're making. Can you state it in 20 words or less?"

4. Step off center. If you're running the meeting from a stage or podium, you can encourage interaction by identifying a topic, asking a question and then moving away from the center of the stage.

5. Let others answer questions. When someone directs a question to you, redirect it back to the group: "Before I answer that, let's see what someone else might say."

6. Think "I," not "we." Encourage people to take ownership of their thoughts and opinions. If someone says "We all think that...." ask if literally everyone in the room believes that or if it's just the speaker's personal opinion.

7. Use a flipchart to track progress. When you record ideas generated or topics covered, people in the meeting will have a sense of accomplishing something.

8. Summarize. Every so often, pause to ask the group, "Where are we at this point? Where do we need to go from here?"

GROUP DISCUSSION

A group discussion (GD) is a simulated exercise, where you cannot suddenly put up a show, since the evaluators will see through you easily. In this page you can find tips on GD and how to handle them to ensure a positive outcome.

Here's how most group discussions work:

• Normally groups of 8-10 candidates are formed into a leaderless group, and are given a specific situation to analyze and discuss within a given time limit.

• The group may be given a case study and asked to come out with a solution for a problem.

• The group may be given a topic and asked to discuss on the same.

A panel will observe the proceedings and evaluate the members of the group.

OBJECTIVE

Lets start from the basic. One needs to know what one's objective in the group is. A good definition of your objective is - to be noticed to have contributed meaningfully in an attempt to help the group reach the right consensus. What does this essentially mean?

1. The first implication is that you should be noticed by the panel. Merely making a meaningful contribution and helping the group arrive at a consensus is not enough. You have to be seen by the evaluating panel to have made the meaningful contribution. What does that mean in practice?

• You must ensure that the group hears you. If the group hears you, so will the evaluator. That does not mean that you shout at the top of your voice and be noticed for the wrong reasons.

• You have to be assertive. If you are not a very assertive person you will have to simply learn to be assertive for those 15 minutes. Remember, assertiveness does not mean being bull-headed or being arrogant.

• And most importantly, you have to make your chances. Many group discussion participants often complain that they did not get a chance to speak. The fact is that in no group discussion will you get a chance to speak. There is nothing more unacceptable in a GD than keeping one's mouth shut or just murmuring things which are inaudible.

• Participate in as many practice GDs as possible before you attend the actual GD. There is nothing like practice to help you overcome the fear of talking in a GD.

2. The second important implication is that making just any sort of contribution is not enough. Your contribution has to be meaningful. A meaningful contribution suggests that

• You have a good knowledge base

• You are able to put forth your arguments logically and are a good communicator.

• The quality of what you said is more valuable than the quantity. There is this myth amongst many group discussion participants that the way to succeed in a group discussion is by speaking loudly and at great length. One could not be more wrong. You must have meat in your arguments.

Therefore, think things through carefully.

Always enter the room with a piece of paper and a pen. In the first two minutes jot down as many ideas as you can.

When you jot down points, keep these pointers in mind.

 If it is a topic where you are expected to take a stand, say for example, "Should India sign the Comprehensive Test Ban Treaty?" note down points for both sides of the argument. It will be useful on two counts -

• One, if you do not start the GD and are not amongst the first five speakers and find that everyone in the group is talking for the topic, then it makes sense to take the alternate approach and oppose the topic even if you initially intended to talk for the topic.

• Second, it helps to have a knowledge of how group members who take a stand diametrically opposite to yours will put forth their argument and be prepared with counter arguments for that.

 Everybody else will state the obvious. So highlight some points that are not obvious. The different perspective that you bring to the group will be highly apprecaited by the panel.

• However, be careful that the "something different" you state is still relevant to the topic being debated?

• Can you take the group ahead if it is stuck at one point?

• Can you take it in a fresh and more relevant direction?

These are some of the other factors that could swing the chances completely in your favour.

3. The third implication is that you must be clearly seen to be attempting to build a consensus.

• Gaining support or influencing colleagues is the mantra adopted by many a successful Business Leaders.

• Nobody expects a group of ten people, all with different points of view on a controversial subject to actually achieve a consensus. But Did you make the attempt to build a consensus?

• The reason why an attempt to build a consensus is important is because in most work situations you will have to work with people in a team, accept joint responsibilities and take decisions as a group.

• You must demonstrate the fact that you are capable and inclined to work as part of a team.

Group Discussion (GD) is a logical extension of the admission tests to assess a candidate’s overall personality. His/her in-depth understanding of the topic, self-confidence, attitude (rigid or flexible temperament) and initiatives in the discussion, presence of mind in crisis management and speaking etiquette are on test.

The strength of a group usually varies between eight and twelve. Unlike the candidates in the written test the group here is homogeneous in terms of proficiency level, since they have crossed the first hurdle, the written test.

A candidate has to discuss a general topic ranging from socio-economic to political issues in about 20 to 25 minutes to amicably conclude the discussion. One’s success essentially hinges on how effectively he or she communicates to deal with the most complex thing in this world i.e., human relationship. One must accentuate the stronger points and abandon the weaker sections. Self-knowledge, rigorous and sustained practice coupled with awareness of non-verbal skills will lead to a winning performance.

Our body expresses many different emotions subconsciously. If a speaker is immensely interested in the subject, truly believes in what is said, and honestly wants to share views with others, the speaker’s physical movements will be naturally spontaneous and appropriate to what is said. Body language has a direct influence on the responses elicited from those around. Therefore, the speaker must be aware of the importance of body language to ensure that there should not be any mismatch with the verbal communication.

Remember "GD" is often undermined by lack of preparation. One should be regularly in touch with national and international current events, debates programs on TV channels, articles and editorials in dailies, magazines and news portals to accumulate one’s knowledge and consolidate one’s views on everything happening around. Unflinching faith, strong commitment and solid implementation plan will see one through the group discussion.

Do’s

1. During discussion make sure that you speak at least five or six times, contributing meaningfully towards discussion. The initial impression your appearance makes is immediately confirmed or contradicted by your voice and words.

2. Put your views persuasively, unobtrusively and modulate your voice accordingly.

3. Be courteous, clear and appear confident to command respect.

4. Have a good attitude. A person with a positive attitude can direct his thoughts; control his emotions and regulate his attitudes.

5. Better to concentrate on one or two ideas at a time to avoid confusion in your development of thought.

6. Words are the vehicle of thought. Pay attention to what others are saying otherwise you may end up making statements that are irrelevant, and you will be labeled as inconsistent as well. Therefore, listen effectively. Try to encourage others without acting impatient. Simply nod and say ‘I see’, or other positive listening words.

7. When your views are challenged you must be able to defend your statement tactfully and convincingly. Be alert and show interest in what others are saying. Analyze your strong points and substantiate them by examples, statistical data to throw light on the topic. Concentrate on what you want to say and how you want to say. Present your points in a logical order to make them interesting.

8. Try to set a good beginning and equally a good ending.

9. Be natural, friendly and cheerful. Friendliness is something of a bonus. Remember you have come to win friends, not to make foes.

10. Speak to the whole group looking at each candidate in turn. Effective eye contact is an important feedback device that makes the speaking situation a two-way communication process. Eye contact binds a speaker with his audience. The adage that ‘eyes are the mirrors of your soul’ underlines the need for you to convince people with your eyes as well as your words. When you speak, your eyes also function as a control device. You can use it to assure your listeners’ attentiveness and concentration. Point out ‘you are about to finish’ – it helps. And do finish with something that group will remember.

Don’ts

1. Resist annoying mannerism. Fidgeting, scratching, picking, shuffling, avoiding eye contact. These are nervous traits. Avoid using filler words like: you know, um etc.

2. Don’t jump upon conclusion to make sweeping generalization. For example, ‘frailty thy name is woman’ – Shakespeare

3. If you are not comfortable with witty comment avoid it.

4. Don’t interrupt others while they are making some points.

5. Don’t scream and use curse words, slang etc.

6. Don’t mumble and talk too softly. Similarly, a wailing or whining voice has an instant depressing effect on others.

7. Don’t speak just for the sake of speaking. Avoid making statements that do not add value to the discussion.

8. Don’t say: ‘You are wrong/ you are being unfair/ I don’t like your ideas.’ Rather refine your argument with:

I understand what you mean and I think …………………

I respect your opinion and I feel …………………..

I agree with you and I want to add …………………….

9. Don’t ramble on and on. Remember quality of the content is more important than the quantity of time you take to speak.

10. Avoid gesturing unnecessarily. You need to be different from others but not in a negative manner.

11. Refrain from using polite fillers: could you please, if you don’t mind etc. They are waste of time.

12. Don’t pack up early.

Replication Manager

2011-02-27T02:15:00.000-08:00

RM and latest SE revs
================

- See primus emc212416 for up-to-date Info

RM                                                         SE

5.0.3 thru 5.1.1                                    6.4.2.20

5.1.2                                                   6.5.0.12
                                                           6.5.0.13
                                                           6.5.0.16
                                                           6.5.0.19
                                                           6.5.0.25

5.1.3                                                   6.5.2.20
                                                           6.5.3.0
                                                           6.5.3.15
                                                           7.0.0.4
                                                           7.0.1.26 (Needed for Flare 29)
                                                           7.1.0.3 (non-windows hosts only)
                                                           7.1.0.17 (Windows only)

5.1.4                                                   6.5.2.20
                                                           6.5.3.0
                                                           6.5.3.15
                                                           7.0.0.4
                                                           7.0.1.26 (Needed for Flare 29)
                                                           7.1.0.3 (non-windows hosts only)
                                                           7.1.0.17 (Windows only)

5.1.5                                                   6.5.2.20
                                                           6.5.3.0
                                                           6.5.3.15
                                                           7.0.0.4
                                                           7.0.1.26 (Needed for Flare 29)
                                                           7.1.0.3 (non-windows hosts only)
                                                           7.1.0.17 (Windows only)

5.1.6                                                   6.5.2.20
                                                           6.5.3.0
                                                           6.5.3.15
                                                           7.0.0.4
                                                           7.0.1.26 (Needed for Flare 29)
                                                           7.1.0.3 (non-windows hosts only)
                                                           7.1.0.17 (Windows only)

5.2.x                                                   6.5.2.20
                                                           6.5.3.0
                                                           6.5.3.15
                                                           7.0.0.4
                                                           7.0.1.26 (Needed for Flare 29)
                                                           7.1.0.3 (non-windows hosts only)
                                                           7.1.0.17 (Windows only)
                                                         7.1.1.18 (replaced 7.1.1.0)
                                                           7.1.2.7 (Needed for Flare 30, however
                                                           RM 5.2.x does not support Flare 30)
                                                          7.1.2.11 (For Linux only)
                                                          7.2.0.0

5.3                                                     6.5.3.0
                                                          7.0.0.4
                                                          7.0.1.26 (Needed for Flare 29)
                                                          7.1.0.3 (non-windows hosts only)
                                                          7.1.0.17 (Windows only)
                                                          7.1.1.18 (replaced 7.1.1.0)
                                                          7.1.2.7 (Needed for Flare 30)
                                                          7.1.2.11 (For Linux only)
                                                          7.2.0.0

5.3.1                                                 7.2.0.0  REQUIRED for RM 5.3.1 !!


RM releases,latest release available and End of Life info

RM 3.0       Service Pack 6      EOL 12/2007

RMSE 3.1 Service Pack 5      EOL 04/2008

RM 4.0       Service Pack 7      EOL 12/2008

RM 5.0       Service Pack 6      EOL 12/2009

RM 5.1       Service Pack 6      EOL 12/2010

RM 5.2       Service Pack 5      EOL 12/2011

RM 5.3       Service Pack 1      EOL 08/2013

Microsoft Hot Fixes

903650 Ext Maint Mode: for w2k3 sp1 ONLY! See emc139668

919117 Ext Maint Mode: for w2k3 sp2 ONLY! See emc139668

934396 VDI for SQL 2000 and 2005 (See Product Guide)

936008 VDS windows 2003 only

978897 VDS Windows 2008 & 2008 SP2

949391 VSS windows 2003 sp1 (see 975928 below for Windows 2003 sp2, because 975928 seems to
Replace all corrected files for sp2 only)

951568 Only needed IF 940349 is installed AND you want need to Turn on Microsoft VSS debugging.

975928 VSS for 2003 SP2, 2008 and 2008 SP2 (No clue why MS didn’t include 2008 sp1)

975832 / 975921 First VSS hot fixes for 2008 that I know of…

975832 for w2k8 R1

975921 for w2k8 R2

NOTE that these 2 hot fixes fix different .exe’s than the ones 975928 fix, so they can be applied as well.

957910 Storport W2K3 (943545 and 950903 are older revs)

968675 W2K8 SP2

951246 Needed only for W2K8 SP1 only! RM Servers for MS scheduling bug

IRIndicator file is located in:

Windows: C:\windows\IRIndicator

Unix /var/sadm/PKG/IR/IRIndicator

RM’s symapi_db.bin file is located in:

C:\Program Files\emc\rm\client\bin\symapi_db_ercrm_client.bin

SE symapi_db file is located in:

C:\Program Files\emc\symapi\db\symapi_db.bin

/var/symapi/db/symapi_db.bin

~~Troubleshooting~~

- Devices not “visable to host” in RM?

For UNIX:

1. Shutdown RM Client service.

/opt/emc/rm/client/bin/rc.irclient stop

2. Shutdown all SE daemons.

/opt/emc/SYMCLI/V6.5.3/bin/stordaemon shutdown all -immediate

3. Rename existing symapi_db.bin file.

mv /var/symapi/db/symapi_db.bin /var/symapi/db/symapi_db.bin.old

4. Rename existing symapi_db_emcrm_client.bin file.

mv /opt/emc/rm/client/bin/symapi_db_emcrm_client.bin /opt/emc/rm/client/bin/symapi_db_emcrm_client.bin.old

5. Run symcfg discover -clar and confirm new symapi_db.bin created, this task start up the SE deamons automatically.

6. Start RM client service.

/opt/emc/rm/client/bin/rc.irclient start

For Microsoft Windows:

1. Right-click RM Client service > Select Stop.

2. Shutdown all SE daemons. Right-click EMC storapid > Select stop.

3. Rename c:\program files\emc\symapi\db\symapi_db.bin to symapi_db.bin.old

4. Rename c:\program files\emc\rm\client\bin/symapi_db_emcrm_client.bin to symapi_db_emcrm_client.bin.old

5. Start up EMC storapid service.

6. Run symcfg discover -clar and confirm new symapi_db.bin created.

7. Start RM client service.

~~Top 10 issues for RM~~

1. Job failures due to the error “cannot locate device x on supported arrays”.

- Steps to fix….stop RM and EMC Storapid services/daemons, and delete the RM and symapi DB’s

- If job still fails, try a “symrslv” on the filesystem and see if that works. If this fails or doesn’t come back with the correct output, symrslv pd on the device should show a “c” beside the device if it’s a Clariion, and an “s” to indicate Symmetrix)

2. VMware concepts.

- Support for Vmware can be broken down into 3 components

VMFS

- Requires a Proxy host…in the application set, you select the VMFS datastore you are replicating and RM will instruct Virtual Centre to take a VSS snapshot of all the VM’s on the VMFS datastore (This can be disabled using the vmsnapdeny.cfg). Proxy host must have placeholder RDM LUN.

- Sometimes with VMFS, you get an error that a snapshot could not be taken of a particular VM on that VMFS volume, but the VM Host ID does not refer to any VM. The easiest way to figure out which VM is giving the problem is to do the following..

If you want to find out the name associated with that ID run the following command from the RM Server:

C:\Program Files\EMC\rm\client\bin>rm_vimclient -h -u -p -ListVMInESX

Look at the line “Disk File Path” of the output. It will tell you the name of the Vmdk that corresponds with the VM having the issue

- The RM_VIMCLIENT (\emc\rm\client\bin) is used by RM to query the Proxy Host for the VMFS information. Syntax of this command is as follows:

rm_vimclient -h -U -P -ListVMFS

Other switches are as follows:

- liststorageadapters

- mapvmfs

- listesx

Virtual Disks

- Requires a proxy host. Not supported for Exchange and Sharepoint as Microsoft VSS is not supported on Virtual disks due to an issue with the SCSI page information restriction with VMware. When Virtual disks are being used, they show up to the VM in syminq.txt as ”Virtual Disks”

RDM’s

- Treat as same as normal fibre disks…no proxy host required. When mounting snaps, you need to create “Placeholder snap sessions from the source LUN’s and present them as RDM devices to the mount host VM. See Primus emc184439

3. Oracle ASM.

- Most common configuration is Oracle ASM on Linux. Linux environments can use ASMlib (library file for Oracle ASM) to address the ASM disks
- Check Oracle ASM config file (/etc/sysconfig/oracleasm)
- Check Oracle ASMlib Log ((/var/log/oracleasm)

- Common ASMLib troubleshooting commands..

On one of the production asm instances: select path from v$asm_disk;
as root : /etc/init.d/oracleasm list disks
as root: /etc/init.d/oracleasm querydisk

- As with all Oracle jobs, the Database user is very important…for Oracle ASM, need to have SYSASM privileges, and with Oracle, need to have SYSDBA

- ASM disks on Linux have to be configured on Partitioned disks.
- OS user is also important especially with regards to mounts and restores.

- Adequate space in /tmp is absolutely vital for saving the archive logs that are needed to be used to mount or restore that Oracle replica. Need about 1 – 2 Gigs free

- If the RM logs do not contain sufficient information, always look for either the Oracle alert log or the Oracle ASM log.

- We do have the following processes that take place during ASM RAC to RAC mounts

A. Creation of ASM init files for all mount RAC nodes

B. Creation of database init file for node chosen as mount host

C. Node reachability check

D. Rescan of ASM disks on remote nodes

E. Propagation of ASM init files created in step 1 to respective nodes.

F. Creation of ASM dump directories.

G. If recovery type is read-only or read-write, the ASM instances are started on all nodes.

H. Rename and propagation of database init file created in step 2 to other nodes. This is because the content of the database init files for all the RAC instances is same, only the names differ.

I. Creation of database dump directories.

J. If recovery type is read-only or read-write, the RAC database instances are started.

See Primus emc234052 for information on an ETA concerning RM and Oracle ASMLlib

4. Oracle issues in general.

- Logging much better in RM 5.2.1 onwards to make debugging easier. To get extra information in the RM logs, you can add a variable to the RC.IRCLIENT to create RM ORA trace files

RM_ORA_TRACE=1
export RM_ORA_TRACE
This will produce trace files in /tmp

In RM 5.3 onwards, these variables can be added via the RM GUI.
As with ASM troubleshooting, main pain points are as follows..
- Permissions of Oracle directories
- Permissions of Oracle DBA account…Needs to have sysdba privileges
- Sufficient space in /tmp

5. CELERRA ISSUES

99% of Celerra issues are not RM bugs…they are Celerra/network issues. The most common issue is with the remote replication failing because of poor network bandwidth between the local site and the remote

- From RM 5.2.4 upwards, you can pretty much discount any issues with RM as long as the Dart code is 5.6.47 or higher.

Celerra Replicator

- The most common issue is with “Celerra Replicator”, which essentially is a remote replication. See the following description of what exactly is taking place during a Celerra Replicator job..

- This creates a local snap, uses that snap as a baseline to copy to a target LUN. Then, it snaps the target LUN. That is your replica. Then, it "deletes" the local snap, but since it’s the source baseline of the replicator session, the celerra won't let it be deleted. It will be deleted later.

- See Primus emc216471 on why Production host needs to have IP connectivity to remote Datamover

- Need port 5033 open for SNAPAPI to work, so if you are getting SNAPAPI errors for a new install/implementation, make sure this port is open

IP issues

- IP issues are also a concern for RM especially for Remote replications using Celerra Replicator. Make sure production host can ping remote datamover.

Celerra NFS issues

- RM 5.3.2 will have all the Celerra NFS hotfixes.

- If your logged into the Celerra via ssh, the following commands :
To list the check point associated with an RM Application Set:

fs_ckpt appsetname -list -all

The jobname will be part of the checkpoint name with date/timstamps and an ID
To delete a Checkpoint:

fs_ckpt -delete id=xxx

6. RM issues on UNIX

Important points to note for UNIX hosts:

- RM does not create an RM symapi DB on Linux, so we use the symapi_db.bin instead
- Storapid process on UNIX is under the control of the stordaemon, so this is the daemon that needs to be stopped if troubleshooting any Solutions Enabler issues

7. Restores on Windows Clusters

- VSS hotfix for Windows 2008 was required to resolve an issue whereby a previous VSS backup failure had left VSS flags on the disks. Microsoft advised installing that hotfix and rebooting all nodes.

- On the odd occasion, you might come across an issue whereby a restore to a cluster is failing due to “Files in use”. RM cannot force unmount or force restore over a file or a disk which has an open handle, so customer needs to use handle.exe or process explorer.exe to find out what process has an open handle.

8. Mirrorview

- Replication Manager Client at least one must be connected and zoned to the REMOTE Clariion arrayThe Mirror View image state must be Synchronized on Consistent and the Secondary condition should NOT be in fractured state.
- There is a long and exhaustive checklist for Mirrorview requirements in the Admin Guide
- Mirrorview enhancement made it into RM 5.3, but hotfixes for all affected versions are now listed in Primus emc229210

9. VSS Imports

- By default, RM uses a process called a “VSS Import” to mount the clone disks to a Windows mount host. If the VSS Import fails, RM will wait for 45 minutes, and then switch to using VDS instead.

- The main advantage of using VSS Imports is due to speed…a VSS Import is much faster than using VDS.VDS mounts take longer because each disk is scanned individually and the time it takes to do this is approx 2 – 3 minutes per disk.

- The main disadvantage of using VSS Imports is that it is liable to be affected by many third party software products. Products like the Qlogic Java Management Agent, many disk Monitoring software, Antivirus, can cause the VSS import to fail.

- These 3rd Party products put a “lock” or “VETO” on the disks being imported, and these VETO’s can be seen from the C:\Windows\setupapi log, which is collected by the EMCreports.

- Primus emc221301 can be used to run “Handle.exe” to debug the VETO’s. This output can then be sent to Microsoft for analysis to determine what is causing the VETO. It must be stressed that this is not an RM issue and the only people who can determine what is causing the VETO is Microsoft.

- You can, or course disable the VSS Import without adversely affecting the replica intergrity. See Primus emc185640 for the registry key details

- It is important to get the customer to check his Antivirus software and make sure that the Antivirus is not scanning the mount point that RM is mounting to.

10. Hints and Tips

A - Support page for RM.
http://supportwip.emc.com/products/ReplicationManager.aspx

B - Steps for uninstalling RM completely from a host if an upgrade fails.

This can be done safely on an RM client, but when upgrading an RM Server at a site, remember to back up the SolidDB first and thr license directory because if the upgrade fails, the SolidDB will be removed.

1. Delete RM services

sc delete "service_name"…for this, you will have the get the "service name" for each of the RM services on the box…to do this, right click on each service and select properties. The service name will be at the top of the page.
2. Remove rm directory from the RM installation location
3. Delete ..\windows\IRIndicator file
4. Delete Replication Manager entries from the registry

C - Cross mounting between Windows 2003 and Windows 2008.

Not supported by Microsoft and as a consequence, not supported by RM. See the following KB article..

Note A shadow copy that was created on Windows Server 2003 R2 or Windows Server 2003 cannot be used on a computer that is running Windows Server 2008 R2 or Windows Server 2008. A shadow copy that was created on Windows Server 2008 R2 or Windows Server 2008 cannot be used on a computer that is running Windows Server 2003. However, a shadow copy that was created on Windows Server 2008 can be used on a computer that is running Windows Server 2008 R2, and vice versa.

http://msdn.microsoft.com/en-us/library/bb968832(VS.85).aspx

D - Scripts in RM

- Manually created customer scripts used for pre/post replication or pre/post

Mount need to have the parameter “exit 0” added to the end of the script, so that if the script is successful, it will return a successful exit code to RM. Otherwise, the RM client will wait indefinetly for a response back from the script.

E - Windows 2008 and Symmetrix arrays

- Primus emc200609 goes into detail about what Symmetrix flags need o be set on the Symmetrix Directors for Windows 2008 hosts. This is really important for mount hosts.

F - Instructions to collect IRCCD crash dump

1- Install the Microsoft Debugging tool on the host ,If there are any concerns about installing it on a production host, then install it on another system and copy the "C:\Program Files\Debugging Tools for Windows" directory over to the server. Use the following links depending upon the OS

Windows 2003: http://www.microsoft.com/whdc/devtools/debugging/installx86.mspx

Windows 2008: http://www.microsoft.com/whdc/devtools/debugging/install64bit.mspx

2- Go to the install folder C:\Program Files\Debugging Tools for Windows (x86)/C:\Program Files\Debugging Tools for Windows (x64)> and run the following command:

cscript adplus.vbs -crash -pn irccd.exe -o c:\irccdcrashdump -quiet
where c:\irccdcrashdump is the destination folder where dump files would be created.

More information is available on the following Microsoft sites:

http://support.microsoft.com/kb/931673/en-us

http://blogs.technet.com/b/askperf/archive/2007/06/15/capturing-application-crash-dumps.aspx

The method of collecting vss trace on Windows 2008 R2

The Primus Solution emc91744 and vssreports method does not work for the Windows 2008 R2 boxes, to get VSS debug logs on these boxes we have to use the "vsstrace" utility which is a part of Windows 7 SDK.To enable VSS logging we have to use the following command:

vsstrace +f 0xffff -o C:\vss_trace.log

Sometimes the -o switch would not work, to workaround this we can use the redirection operator ">" to specify the output file.So now the command looks like the following:

vsstrace +f 0xffff >C:\vss_trace.log

More details about this process is on the following Microsoft technet article:
http://msdn.microsoft.com/en-us/library/dd765233(v=VS.85).aspx

CLARIION Environment & Application Integration

2010-04-28T09:33:00.000-07:00

Topics:

1. Zoning
2. Host to Clariion Configurations
3. Host Connectivity Limitations
4. Storage Processor Ports WWNs
5. Caching
6. Cache Allocation
7. Cache Page Size
8. Enclosure Types
9. Cache WaterMarks
10. Verifying RAID Group Disk Order
11. LUN Layout
12. Calculating the Stripe Size of a LUN
13. Setting the Alignment Offset on ESX Server and a (Virtual) Windows Server
14. Setting Raid Group Command Parameters
15. Setting Cache Command Parameters
16. Setting the Alignment Offset for windows & Linux servers
17. Disk Alignment
18. LUN Migration
19. MetaLUNs
20. Access Logix
21. Clariion Disk Format
22. Disk Format
23. LUNs
24. Order of Disks in RAID Group for RAID 1_0
25. RAID GROUPS and RAID Types
26. Vault Drives
27. General Commands for Navisphere CLI

================================================================

Zoning

How a Host might be zoned through switches to a Clariion.

This host has two(2) Host Bus Adapters. From the previous page, we know that the host must have at least one connection to SP A and one connection to SP B. What we are illustrating here is from the “Host to Clariion Configuration” page, Configuration Three. We are also going to look at what is meant by “Single Inititiator Zoning”. Single Initiator Zoning means that you create a zone with one HBA entry. We don’t want to have a zone that would contain an HBAs from two(2) Hosts.

HBA1 is connected to Port 0 on the switch. SP A port 0 is connected to the same switch at Port 14. Based on the World Wide Names of HBA1 and SP A port 0, we can now create a zone through the switch software. The zone could look as follows:

Zone HBA1 to SP A port 0

10:00:00:00:07:36:55:86

50:06:01:60:10:60:08:74

We also want to connect HBA1 to SP B. We connect SP B port 0 to Port 15 on the same switch. That zone could look as follows:

Zone HBA1 to SP B port 0

10:00:00:00:07:36:55:86

50:06:01:68:10:60:08:74

HBA1 is now zoned and connected to both Storage Processors on the Clariion.

We would repeat the same steps for HBA2 and the switch that it is connected to. HBA2 is connected to Port 0 on the switch. SP A port 1 is connected to the same switch at Port 14. Based on the World Wide Names of HBA1 and SP A port 1, we can now create a zone through the switch software. The zone could look as follows:

Zone HBA2 to SP A port 1

10:00:00:00:66:87:35:20

50:06:01:61:10:60:08:74

We also want to connect HBA2 to SP B. We connect SP B port 1 to Port 15 on the same switch. That zone could look as follows:

Zone HBA2 to SP B port 1

10:00:00:00:66:87:35:20

50:06:01:69:10:60:08:74

Another way in which the zoning could have been done is:

Zone HBA1 to SP A port 0 and SP B port 0

10:00:00:00:07:36:55:86

50:06:01:60:10:60:08:74

50:06:01:68:10:60:08:74

Again, there is only one HBA in that zone. The preferred method is simply up to you and how you want to manage the switches. The advantage of doing it this way is that it cuts the number of zones on the switch in half, but could be a little confusing (which could be nice for job security).

Now, what do we do if there is an HBA failure? First of all, that never happens. (Kidding) This is where we go to the four(4) steps listed under HBA Failure. The three R’s and a D. Let’s say that HBA1 were do fail. The first thing we would do is to replace that failed HBA. Next, because we did our zoning on the switch based on the World Wide Names of the HBAs, we would have to rezone the switch for the new HBA because it would have a new World Wide Name. The third step is to go to Navisphere, and using Connectivity Status, Register the new HBA with the Clariion. And finally, the Clariion does not automatically clean itself up. You would have to again, in Connectivity Status, Deregister the failed HBA.

Host to Clariion Configurations

Here we are looking at only three possible ways in which a host can be attached to a Clariion. From talking with customers in class, these seem to be the three most common ways in which the hosts are attached.

The key points to the slide are:

1. The LUN, the disk space that is created on the Clariion, that will eventually be assigned to the host, is owned by one of the Storage Processors, not both.

2. The host needs to be physically connected via fibre, either directly attached, or through a switch.

CONFIGURATION ONE

In Configuration One, we see a host that has a single Host Bus Adapter (HBA), attached to a single switch. From the Switch, the cables run once to SP A, and once to SP B. The reason this host is zoned and cabled to both SPs is in the event of a LUN trespass. In Configuration One, if SP A would go down, reboot, etc...the LUN would trespass to SP B. Because the host is cabled and zoned to SP B, the host would still have access to the LUN via SP B. The problem with this configuration is the list of Single Point(s) of Failure. In the event that you would lose the HBA, the Switch, or a connection between the HBA and the Switch (the fibre, GBIC on the switch, etc...), you lose access to the Clariion, thereby losing access to your LUNs.

CONFIGURATION TWO

In Configuration Two, we have a host with two Host Bus Adapters. HBA1 is attached to a switch, and from there, the host is zoned and cabled to SP B. HBA2 is attached to a separate switch, and from there , the host is zoned and cabled to SP A. The path from HBA2 to SP A, is shown as the "Active Path" because that is the path data will leave the host from to get to the LUN, as it is owned by SP A. The path from HBA1 to SP B, is shown as the "Standby Path" because the LUN doesn't belong to SP B. The only time that the host would use the "Standby Path" is in the event of a LUN Trespass. The advantage of using Configuration Two over Configuration One, is that there is no single point of failure.

Now, let's say we install PowerPath on the host. With PowerPath, the host has the potential to do two things. First, it allows the host to initiate the Trespass of the LUN. With PowerPath on the host, if there is a path failure (HBA gone bad, switch down, etc...), the host will issue the trespass command to the SPs, and the SPs will move the LUN, temporarily, from SP A to SP B. The second advantage of PowerPath on a host, is that it allows the host to 'Load Balance' data from the host. Again, this has nothing to do with load balancing the Clariion SPs. We will get there later. However, in Configuration Two, we only have one connection from the host to SP A. This is the only path the host has and will use to move data for this LUN.

CONFIGURATION THREE

In Configuration Three, hardware wise, we have the same as Configuration Two. However, notice that we have a few more cables running from the switches to the Storage Processors. HBA1 is into the switch and zoned and cabled to SP A and SP B. HBA2 is into the switch and zoned and cabled to SP A and SP B. What this does now is to give HBA1 and HBA2 an 'Active Path' to SP A, and HBA1 and HBA2, 'Standby Paths' to SP B. Because of this, the Host now can route data down each active path to the Clariion, allowing the host "Load Balancing" capabilities. Also, the only time a LUN should trespass from one SP to another is if there is a Storage Processor failure. If the host were to lose HBA1, it still has HBA2 with an active path to the Clariion. The same goes for a switch failure and connection failure.

Host Connectivity Limitations

This page is going to discuss how many hosts can connect to a Clariion. The deciding factor in this is going to be the number of times you connect your host(s) to the Clariion. We are going to use the three configurations that were discussed in the prevoius blog. The chart above lists the number of ports each Storage Processor contains based on the model, as well as the number of Initiator Registration Records each port supports. An Initiator Registration Record (IRR) is used everytime a host, via an HBA, is connected and "Registered" with the Clariion. The Clariion now recognizes that this HBA belongs to a specific host attached to the Clariion, and will now allow the host to "talk" with the Clariion. The more times you connect and register a host, the more IRRs it uses, thus taking away potential connections for other or more hosts.

With Configuration One, even though it only has one HBA, that HBA must be connected at least once to SP A and once to SP B. Again, this goes back to the previous blog about access to the Clariion if a LUN were to trespass. Therefore, this host is using two IRRs.

With Configuration Two, this host has one connection from each HBA to one SP Port on each Storage Processor. Even though this host has two HBAs, it is still only using two IRRs. One connection to SPA, one connection to SP B.

With Configuration Three, this host has two connections to the Clariion from each HBA. HBA1 is connected once to SPA and once to SP B. HBA2 is connected once to SP A and once to SP B. This host is using four IRRs because it is connected four times to the Clariion.

In the chart, we are trying to illustrate the maximum number of hosts that can connect to a Clariion based on the host configurations. Again, the more times you connect a host, the more IRRs you use, the less the number of hosts that can be attached to a Clariion. If you are using a CX700, CX3-40 or CX3-80, you have the possibility of hooking up 256 hosts based on each host only having one connection to SP A and one connection to SP B. However, if every host were connected four(4) times, as in Configuration three, that number is cut in half to 128 hosts. If every host were connected to the Clariion eight(8) times, the number is cut again to 64 hosts.

Storage Processor Ports WWNs

Each Storage Processor Port will have a unique World Wide Name associated with it. What we are doing on this page is to “break down” what makes up the SP Port WWN. What I am showing here are the three(3) pieces that make up the WWN. The three(3) pieces are what I am calling the ‘EMC Flag’, the SP Port Identifier, and the Array ID. All SP Port WWNs on Clariions start with the same ‘EMC Flag’ of 50:06:01. When you are looking at the Switch Software that shows the ports on the switch and what is plugged into those ports, anytime you see a World Wide Name that starts with the 50:06:01, you will know that a Clariion SP Port is connected there.

The next “piece” to the World Wide Name, is the SP Port Identifier. On all Clariions, these numbers are the same as well. For instance, if you have 3 Clariions in your environment, every one of those Clariion’s SPA Port 0 World Wide Name would start off 50:06:01:60. And every Clariion’s SP B Port 1 would start off 50:06:01:69. These SP Port Identifiers will not change from Clariion to Clariion.

The last “piece” to the puzzle is the Array ID. This is related to the Unique ID of the Clariion itself. Every Clariion has a unique World Wide Name associated with it. But, that Array ID belongs to every port on that Clariion as it shows above. Now, if you have two(2) Clariions in your environment, you will see two(2) sets of Array IDs. Let’s say you have a Production Clariion and a Development Clariion (I know, no one has that), the Production Clariion could have an Array ID of 10:60:08:74, and the Development Clariion could have an Array ID of 10:60:06:23. So, the Production Clariion’s SP A Port 0 would be 50:06:01:60:10:60:08:74, and the Development Clariion’s SP A Port 0 would be 50:06:01:60:10:60:06:23.

Caching

From the chart above, the amount of Cache that a Clariion contains is based on the model.

Read Caching

First, we will describe the process of when a host issues a request for data from the Clariion.

1.The host issues the request for data to the Storage Processor that owns the LUN. If that data is sitting in Cache on the Storage Processor,

2.The SP sends the data back to the host.

If however, the data is not in Cache, the Storage Processor must go to disk now to retrieve the data. (Step 1 ½ ). It reads the data from the LUN into Read Cache of the owning Storage Processor. (Step 1 ¾ ) before it sends the data to the host.

Write Caching

1.The host writes a block of data to the LUN’s owning Storage Processor.

2.The Storage Processor MIRRORs that data to the other Storage Processor.

3.The owning Storage Processor then sends the Acknowledgement back to the host, that the data is “on disk.”

4.At a later time, the data will be “flushed” from Cache on the SP out to the LUN.

Why does Write Cache MIRROR the data to the other Storage Processor before it sends the acknowledgement back to the host?

This is done to ensure that both Storage Processors have the data in Cache in the event of an SP failure. Let’s say that the owning Storage Processor crashed (again, never happens). If that data was not written to the other Storage Processor’s Cache, that data would be lost. But, because it was written to the other SP Cache, that Storage Processor can now write that data out to the LUN.

This MIRRORing of Write Cache is done through the CMI (Clariion Messaging Interface) Channel which lives on the Clariion.

Cache Allocation

Cache Allocation

In the illustration above, we are seeing again that if data is written to one Storage Processor, it is MIRRORed to the other Storage Processor.

A host that writes data to SP A, will mirror to SP B, and vice versa. So, you will be losing some Cache space to this mirroring. In this example, we are setting SP A’s Write Cache to 1 ½ GB. Which means that over on SP B, 1 ½ GB of Cache space will be taken for the Mirroring of SP A’s Write Cache. The same scenario is set for SP B. The same values are transferred across SPs for Write Cache.

SP Usage

SP Usage is pre-allocated Cache Space that is used by the Clariion for things like pointers/deltas, SnapView, MirrorView. The amount of space that is lost per Storage Processor for SP Usage depends on a couple of things. First, is the type of Clariion you have. Second, what Flare Code you are running on the Clariion. We’ll talk later where to find the Flare Code your Clariion is running.

In this example, we are using 750 MB per Storage Processor as the vaule for SP Usage. To give you some real numbers:

Type of Clariion Flare Code SP Usage:

CX3-80 26 1464 MB

CX3-80 24 1464 MB

CX700 26 884 MB

CX700 24 832 MB

After Write Cache is allocated and SP Usage is taken into account, this leaves us with 250 MB of Cache for Reads.

The nice thing about the Clariion though is that it allows you to change those cache values. Let’s say for instance, that this initial setup above works for you in the mornings when people are writing to a database, but later in the day, the database has more reads. You can take from Write Cache and give the rest to Read Cache. The other nice thing about it is that it can be scripted from the Command Line Interface. Below the chart are the three commands that you can use to change cache.

Command One

Before we can change the values of Cache, we must first disable Cache. This command is the command to disable Write Cache, Read Cache of SP A and SP B. Not only does this disable Cache, it also forces a Flush of Cache to disk. This means that the command prompt will not return immediately. There will be a delay in the command prompt returning until Cache is flushed. As I always say, I cannot give you an amount of time that this will take (two weeks). The answer is going to be….”it depends, you’ll have to test it.”

Command Two

This is the actual setting of Cache command. By default, the setting of Cache is allocated in MegaBytes. By setting Write Cache to 2048 MB (2 GB), we are telling the Clariion to take that number, and divide half of it for SP A Write Cache, and half for SP B Write Cache. We don’t calculate into this the Mirroring of Write Cache, just the actual usable space. Next, we specify the amount for the Read Cache Size of SP A of 1250 MB (1.25 GB) and the Read Cache Size of SP B of 1250 MB (1.25 GB). Read Caching is not Mirrored, so we must specify both SPs Read Cache. Notice how by simply taking ½ GB away from SP A and SP B Write Cache, we can allocate 1 GB more of Cache space to the SPs for Reads.

Command Three

Finally, we have to re-enable Cache. The ones (1) next to –wc, -rca, and –rcb stand for Enabling.

Changing the values of Cache could be done at any time, all day long if you want to, though I wouldn’t recommend it. But, it could prove to be extremely beneficial to performance of the Clariion. Acknowledgements from Writes, and Reading from Cache is going to happen in Nanoseconds as opposed to milliseconds coming from disk.

Another example of why to change Cache could be when Backups are going to occur. Since you will be reading data from Clariion Luns, you could allocate as much Cache to Reads as possible so that the Backup Host could be retrieving data from Cache rather than disk. When the Backups are complete, you could script that the Cache values go back to Production Levels.

Cache Page Size

Here we are discussing the use of the Cache Page Size. We say that it is the same as saying Cache Block Size. Each “Page” or block in Cache is a fixed size. And, in the Clariion, the entire Cache is the same fixed size. Therefore, we feel that this is one of the areas in Cache where knowing your environment (applications, etc) can make a difference. In the diagram above, we are illustrating the use of Cache with three different applications, Oracle, SQL, and Exchange. Next to the applications is a Block Size. We are using these three applications in this diagram because these seem to be the most common applications people come to class with.

Next to the applications is a default Block Size. Again, we are only using these as examples. You want to verify the applications running on the Clariion and their Block Sizes.

There are four different Page Size Settings in Cache for the Clariion, 2 KB, 4 KB, 8 KB, and 16 KB. Let’s start with the default Clariion Page Size of 8 KB. Again, every “Page” in Cache will be 8 KB in size. If we have an application like Oracle running on this Clariion, and Oracle using a default Block Size of 16 KB, that would mean that every Oracle Block of data to the Clariion would be broken into two separate Pages in Cache. With SQL writing to this 8 KB Page Size, it is a one to one ratio, as it is with Exchange, however, with every Exchange Block of data, there is a 4 KB waste of space per block, which could be filling up Cache more rapidly with this “wasted space.”

The next Page Size down shows a 4 KB Page Size for Cache. The nice thing about this size in Cache is that there is no wasted space. Exchange is still in a 1:1 ratio of blocks. However, SQL now has to split into two separate Cache Pages, and Oracle splits into four separate Cache Pages. The good thing about this size is “No Wasted Space.” The down side to this is now we have to listen to the Oracle and SQL admins complain about performance.

So, we set the Page Size to 16 KB to appease the Oracle and SQL admins. Here comes the problem again of wasted space in cache, which, depending on your Clariion, you don’t have a lot of. With the 16 KB Page Size, all of the applications write to one Cache Page. The applications are happy because of this, but we are back to the wasted space. For every Exchange block written to the Clariion, there is a waste of 12 KB Cache space. For every SQL Block, there is a waste of 8 KB Cache Space.

If you are only using one of these applications on the Clariion, great, match the Cache Page Size to that application. If that is not the case, you as the Storage Administrator, will have to decide the Winners and Losers. Next to each of the different page sizes, we have listed the Winners, and the Losers.

In the 8 KB Page Size, SQL and Exchange are winners because from the application point of view, they are a 1:1 ratio. Oracle is a Loser because it is split across two separate blocks in Cache. Another loser in this setting is the Clariion Cache because of the wasted space.

In the 4 KB Page Size, Exchange and Cache are winners because Exchange is again a ratio of 1:1, and no wasted space in Cache. Oracle and SQL are losers because they are written to separate Pages in Cache.

With the 16 KB Page Size, the applications all win. Oracle, SQL and Exchange are all a 1:1 ratio. The big loser in this setting is Cache. Cache is a loser with all of the wasted space.

This, again is one of the places to look at for performance of Cache in a Clariion. Knowing your environment plays a big piece in how things are written to Cache.

Enclosure Types

Enclosure Types

The above page diagrams the back-end structure of a Clariion. How the disks are laid out. Before we discuss the back-end bus structure, we should discuss the different types of enclosures that the Clariion contains.

1.DAE. The Disk Array Enclosure. Disk Array Enclosures exist in all Clariions. DAE’s are the enclosures that house the disks in the Clariion. Each DAE is holds fifteen (15) disks. The disks are in slots that are numbered 0 to 14.

2.DPE. The Disk Processor Enclosure. The Disk Processor Enclosure is in the Clariion Models CX300, CX400, CX500. The DPE is made up of two components. It contains the Storage Processors, and the first fifteen (15) disks of the Clariion.

3.SPE. The Storage Processor Enclosure. The Storage Processor Enclosure is in the Clariion Models CX700 and the CX-3 Series. The SPE is the enclosure that houses the Storage Processors.

The diagrams above lay out the DAE’s back-end bus structure. Data that leaves Cache and is written to disk, or data that is read from disk and placed into Cache travels along these back-end buses or loops. Some Clariions have one back-end bus/loop to get data from enclosure to enclosure. Others have two and four back-end buses/loops to push and pull data from the disks. The more buses/loops, the more expected throughput for data on the back-end of the Clariion.

The Clariion Model on the left is a diagram of a CX300/CX3-10 and CX3-20. These models have a single back-end bus/loop to connect all of the enclosures. The CX300 will have one back-end bus/loop running at a speed of 2 GB/sec, while the CX3-Series Clariions have the ability to run up to 4 GB/sec on the back-end.

The Clariion Model in the middle is a diagram of a CX500. The CX500 has two back-end buses/loops. This gives the CX500, twice the amount of potential throughput for I/Os than the CX300.

The Clariion Model on the right is a diagram of a CX700, CX3-40 and CX3-80. These Clariions contain four back-end buses/loops. The CX3-80 will contain the maximum back-end throughput with all four buses having the ability to run at a 4 GB/sec speed.

Each enclosure has a redundant connection for the bus that it is connected. This is in the event that the Clariion loses a Link Control Card (LCC) that allow the enclosures to move data, or the loss of a Storage Processor. You will see one bus cabled out of SP A and SP B, allowing both SP’s access to each enclosure.

Enclosure Addresses

To determine an address of an enclosure, we need to know two things, what bus it is on, and what number enclosure it is on that bus. On the Clariions in the left diagram, there is only one back-end bus/loop. Every enclosure on these Clariions will be on Bus 0. The enclosure numbers start at zero (0) for the first enclosure and work their way up. On these Clariions, the first enclosure of disks is labeled Bus 0_Enclosure 0 (0_0). The next enclosure of disks is going to be Bus 0_Enclosure 1 (0_1). The next enclosure of disks 0_2, and so on.

The CX500, with two back-end buses will alternate enclosures with the buses. The first enclosure of disks will be the same as the Clariions on the left of Bus 0_Enclosure 0 (0_0). The next enclosure of disks will utilize the other back-end bus/loop, Bus 1. This enclosure is Bus 1_Enclosure 0 (1_0). It is Enclosure 0, because it is the first enclosure of disks on Bus 1. The third enclosure of disks is going to be back on Bus 0, 0_1. The next one up is on Bus 1, 1_1. The enclosures will continue to alternate until the Clariion has all of the supported enclosures. You might ask why it is cabled this way, alternating buses. The reason being is that most companies don’t purchase Clariions fully populated. Most companies buy disks on an as needed basis. By alternating enclosures, you are using all of the back-end resources available for that Clariion.

The Clariions on the right show the four bus structure. The first enclosure of disks is going to be Bus 0_Enclosure 0 (0_0) as all other Clariions. The next enclosure of disks is Bus 1_Enclosure 0 (1_0). Again, using the next available back-end bus, and being the first enclosure of disks on that bus. The third DAE is going to be Bus 2_Enclosure 0 (2_0). The fourth DAE is on the fourth and last back-end bus. It is Bus 3_Enclosure 0 (3_0). From here, we are back to Bus 0 for the next enclosure of disks. Bus 0_Enclosure 1 (0_1). The next DAE is 1_1. The next would be 2_1 if we had one. 3_1, 0_2, and so on until the Clariions were fully populated.

Disk Address

The last topic for this page are the disks themselves. To find a specific disk’s address, we use the Enclosure Address and add the Slot number the disk is in. This gives us the address that is called the B_E_D. Bus_Enclosure_Disk. The Clariion on the left has a disk in slot number 13. The address of that disk would be 0_2_13. The Clariion in the middle has a disk in slot number 10 of Enclosure 1_1. This disk address would be 1_1_10. And the Clariion on the right has a disk in Bus 2_Enclosure 0. It’s address is 2_0_6. And the disk in Bus 1_Enclosure 1 is in slot 9. Address = 1_1_9.

Finally, each Clariion has a limit to the number of disks that it will support. The chart below the diagrams provides the number of how many disks each model can contain. The CX300 can have a maximum of 60 disks, whereas the CX3-80 can have up to 480 disks.

The importance of this page is to know where the disks live in the back of the Clariion in the event of disk failures, and more importantly how you are going to lay out the disks. Meaning, what applications on going to be on certain disks. In order to put that data onto disks, we have to create LUNs (will get to it), which are carved out of RAID Groups (again, getting there shortly). RAID Groups are a grouping of disks. To have a nice balance and to achieve as much performance and throughput on the Clariion, we have to know how the Clariion labels the disks and how the DAE’s are structured.

Cache WaterMarks

WaterMarks :

WaterMarks is what controls writing data out of Cache to disk. It is used to manage how long data stays in Write Cache before it is written to disk.

This diagram is used to describe the types of “Flushing” data to disk, or writing data out of Cache to disk.

The first type of Write Cache Flushing is Idle Flushing.

Idle Flushing is when the Clariion has the ability to take the ‘writes” into cache, send the acknowledgement back to the host that the data is on “disk.” While this is happening, the Clariion can also write data out to disk. The Clariion will try to write to disk in a 64 KB “Chunk.” The cache is absorbing the writes, grouping them together, and writing them to disk. This will come into play later when we discuss how the Clariion formats the disks. This is the perfect case scenario. The Cache takes in the writes, the Clariion has the resources to write the blocks to disk.

The second type of Flushing is WaterMark Flushing.

This is maintained by percentages that you can configure in Cache. The goal with WaterMark Flushing is to keep the Write Cache level between these two percentages. We are using the default Low WaterMark Setting of 60%, and High WaterMark Setting of 80%. These can be changed, and we will discuss that later. With WaterMark Flushing, Cache is going to do it’s best to keep Write Cache between these two levels. As Write Cache hits the High WaterMark, the Clariion tries to flush down to the Low WaterMark. If the amount of Write Cache is constantly between these two levels, the Clariion is doing its job.

The last type of flushing is the “Forced Flush.”

A Forced Flush of Cache results in the Write Cache reaching capacity. The Clariion will no longer accept data into write cache, as there is no more room.

When a Forced Flush occurs, the following take place:

1. The Clariion disables Write Cache.

2. The Clariion begins to destage/flush the write data in Cache out to disk.

3. Now comes the performance issue. With the Clariion disabling Write Cache, any new writes that come in from a host will bypass cache and be written directly to disk. The host/application is now waiting for the acknowledgement to return after the data was written to disk.

4. The Clariion will keep Write Cache disabled until it flushes to the Low WaterMark.

5. Once Write Cache is flushed to the Low WaterMark level, Write Caching is automatically re-enabled.

Verifying RAID Group Disk Order

The examples above are from an output of running the get Raid Group command from Navisphere Command Line Interface.

Both RAID Groups are configured as Raid type 1_0.

In an earlier blog we discussed the importance of configuring RAID 1_0 by separating the Data disks and Mirrored Disks across multiple buses and enclosures on the back of the Clariion. This diagram is to show how you could verify if a RAID 1_0 Group is configured correctly or incorrectly.

The reason we are showing the output of the RAID Groups from the command line is this is the only place to truly see if the RAID Groups were configured properly.

The GUI will show the disks as the Clariion sees them in the order of the Bus and Enclosure, not the order you have placed the disks in the RAID Group.

LUN Layout

This diagram shows three different ways in which the same 6 LUNs could be laid out on a RAID Group

In example number 1, the two heavily utilized LUNs have been placed at the beginning and end of the LUNs in the RAID Group, meaning they were the first and last LUNs created on the RAID Group, with lightly utilized LUNs between them. Why this could be a disadvantage to the LUNs, RAID Group, Disks, is that Example 1 would see a much higher rate of Seek Distances at the Disk Level. With a higher Seek Distance rate, comes greater latency, and longer response times for the data. The head has to travel, on average a greater distance between the two busiest LUNs across the disks.

Example 2 has the two heavily utilized LUNs adjacent to each other at the beginning of the RAID Group. While this is the best case scenario for the two busiest LUNs, it could also result in high Seek Distances at the Disk Level because the head would be traveling between the busiest LUNs and then seeking a great distance on the disk when access is needed to the less needed LUNs.

Example 3 shows the heavily utilized LUNs placed in the center of the RAID Group. The advantage to this configuration is the head of the disk would remain between the two busiest LUNs, and then would have a much shorter seek distance to the less utilized LUNs on the outer and inner edge of disks.

The problem with these types of configurations, is that for the most part, it is too late to configure the LUNs in such a way. However, with the use of LUN Migrations in Navisphere, and enough unallocated Disk Space, this could be accomplished while having the LUNs online to the hosts. You will however see an impact on the performance of these LUNs during this Migration process.

But, if performance is an objective, it could be worth it in the long run to make the changes. When LUNs and RAID Groups are initially configured, we usually don’t know what type of Throughput to expect. After monitoring and using Navisphere Analyzer, we could at a later time, begin to move LUNs with heavier needs off of the same Raid Groups, and onto Raid Groups with LUNs not so heavily accessed.

Callculating the Stripe Size of a LUN

To calculate the size of a stripe of data that the Clariion writes to a LUN, we must know how many disks make up the Raid Group, as well as the Raid Type, and how big a chunk of data is written out to a disk. In the illustration above, we have two examples of Stripe Size of a LUN.

The top example shows a Raid 5, five disk Raid Group. We usually hear this referred to as 4 + 1. That means that of the five disks that make up the Raid Group, four of the disks are used to store the data, and the remaining disk is used to store the parity information for the stripe of data in the event of a disk failure and rebuild. Let’s base this on the Clariion settings of a disk format in which it formats the disk into 128 blocks for the Element Size (amount of blocks written to a disk before writing/striping to the next disk in the Raid Group), which is equal to the 64 KB Chunk Size of data that is written to a disk before writing/striping to the next disk in the Raid Group. (see blog titled DISK FORMAT)

To determine the Data Stripe Size, we simply calculate the number of disks in the Raid Group for Data (4) x the amount of data written per disk (64 KB), and get the amount of data written in a Raid 5, Five disk Raid Group (4 + 1) as 256 KB of data. To get the Element Stripe Size, we calculate the number of disks in the Raid Group (4) x the number of blocks written per disk (128 blocks) and get the Element Stripe Size of 512 blocks.

The bottom example illustrates another Raid 5 group, however the number of disks in the Raid Group is nine (9). This is often referred to as 8 + 1. Again, eight (8) disks for data, and the remaining disk is used to store the parity information for the stripe of data.

To determine the Data Stripe Size, we simply calculate the number of disks in the Raid Group for Data (8) x the amount of data written per disk (64 KB), and get the amount of data written in a Raid 5, Five disk Raid Group (8 + 1) as 512 KB of data. To get the Element Stripe Size, we calculate the number of disks in the Raid Group (8) x the number of blocks written per disk (128 blocks) and get the Element Stripe Size of 1024 blocks.

The confusion usually comes across in the terminology. The Stripe Size again is the amount of data written to a stripe of the Raid Group, and the Element Stripe Size is the number of blocks written to a stripe of a Raid Group.

Setting the Alignment Offset on ESX Server and a (Virtual) Windows Server

To add to the layer of confusion, we must discuss what needs to be done when assigning a LUN to an ESX Server, and then creating the (virtual) disk that will be assigned to the (Virtual) Windows Server.

As stated in the previous blog titled Disk Alignment, we must align the data on the disks before any data is written to the LUN itself. We align the LUN on the ESX Server because of the way in which a Clariion Formats the Disks in the 128 blocks per disk (64 KB Chunk) and the metadata written to the LUN from the ESX Server. Although, it is my understanding that ESX Server v.3.5 takes care of the initial offset setting of 128.

The following are the steps to align a LUN for Linux/ESX Server:

Execute the following steps to align VMFS

1. On service console, execute “fdisk /dev/sd”, where sd is the device on which you would like to create the VMFS

2. Type “n” to create a new partition

3. Type “p” to create a primary partition

4. Type “1” to create partition #1

5. Select the defaults to use the complete disk

6. Type “x” to get into expert mode

7. Type “b” to specify the starting block for partitions

8. Type “1” to select partition #1

9. Type “128” to make partition #1 to align on 64KB boundary

10.Type “r” to return to main menu

11.Type “t” to change partition type

12. Type “1” to select partition 1

13. Type “fb” to set type to fb (VMFS volume)

14. Type “w” to write label and the partition information to disk

Now, that the ESX Server has aligned it’s disk, when the cache on the Clariion starts writing data to the disk, it will start writing data to the first block on the second disk, or block number 128. And, because the Clariion formats the disks in 64 KB Chunks, it will write one Chunk of data to a disk.

If we create a (Virtual) Windows Server on the ESX Server, we must take into account that when Windows is assigned a LUN, it will also want to write a signature to the disk. We know that it is a Virtual Machine, but Windows doesn’t know that. It believes it is a real server. So, when Windows grabs the LUN, it will write it’s signature to the disk. See blog titled DISK ALIGNMENT. Again, the problem is that the Windows Signature will take up 63 blocks. Starting at the first block (Block # 128) on the second disk in the RAID Group, the Signature will write halfway across the second disk in the raid group. When Cache begins to write the data out to disk, it will write to the next available block, which is the 64th block on the second disk. In the top illustration, we can see that a 64 KB Data Chunk that is written out to disk as one operation will now span two disks, a Disk Cross. And from here on out for that LUN, we will see a Disk Cross because there was no offset set on the (Virtual) Windows Server.

In the bottom example, we see how the offset was set for the ESX Server, the offset was also set on the (Virtual) Windows Server, and now Cache will write out to a single disk in 64 KB Data Chunks, therefore limiting the number of Disk Crosses.

Again, from the (Virtual) Windows Server we can set the offset for the LUNs using either Diskpart or Diskpar.

To set the alignment using Diskpart, see the earlier Blog titled Setting the Alignment Offset for 2003 Windows Servers(sp1).

To set the alignment using Diskpar:

C:\ diskpar –s 1

Set partition can only be done on a raw drive.

You can use Disk Manager to delete all existing partitions

Are you sure drive 1 is a raw device without any partition? (Y/N) y

----Drive 1 Geometry Information ----

Cylinders = 1174

TracksPerCylinder = 255

SectorsPerTrack = 63

BytesPerSector = 512

DiskSize = 9656478720 (Bytes) = 9209 (MB)

We are going to set the new disk partition.

All data on this drive will be lost. Continue (Y/N) ? Y

Please specify the starting offset (in sectors) : 128

Please specify the partition length (in MB) (Max = 9209) : 5120

Done setting partition

---- New Partition information ----

StatringOffset = 65536

PartitionLength = 5368709120

HiddenSectors = 128

PartitionNumber = 1

PartitionType = 7

As it shows in the bottom illustration from above, the ESX server has set an offset, the (Virtual) Windows Machine has written it’s signature, and has set the offset to start writing data to the first block on the third
disk in the Raid Group.

Setting Raid Group Command Parameters

Setting Cache Command Parameters

Disk Alignment

This is one of the most crucial pieces that we can talk about so far regarding performance. Having the disks that make up the LUN misaligned can be a performance impact of up to 30% on an application. The reason this occurs is because of the “Signature” or MetaData information that a host writes to the beginning of a LUN/Disk. To understand this we must first look at how the Clariion formats the LUNs.

In an earlier blog, we described how the Clariion formats the disks. The Clariion formats the disks in blocks of 128 per disk, which is equivalent to a 64 KB of data that is written to a disk from Cache. Why this is a problem, is that when an Operating System like Windows, grabs the LUN, it wants to initialize the disk, or write a disk signature. The size of this disk signature is 63 blocks, or 31 ½ KB of disk space. Because the Clariion formats the disks in 128 blocks, or 64 KB of disk space, that leaves 65 blocks, or 32 KB of disk space remaining on the first disk for the host to write data. The problem is that the host writes to Cache in whatever block size it does. Cache then holds the data a writes the data out to disk in a 64 KB Data Chunk. Because of the “Signature”, the 64 KB Data Chunk now has to go across two physical disks on the Clariion. Usually, we say that hitting more disks is better for performance. However, with this DISK CROSS, performance will go down on a LUN because Cache is now waiting for an acknowledgement from two disks instead of one disk. If one disk is overloaded with I/O, a disk is failing, etc…this will cause a delay in the acknowledgement back to the Storage Processor. This will be the case from now on when Cache writes every chunk of data out to this LUN. This will impact not only the LUN Cache is writing too, but to every LUN on the Raid Group may be affected.

By using an offset on a LUN from a Host Based Utility, ie Diskpart, or Diskpar for Windows, we are allowing the Clariion to write a 64 KB Data Chunk to one physical disk at a time. Essentially, what we are doing is giving up the remaining disk space on the first physical disk in the Raid Group as the illustration shows above. Window’s still writes it’s “Signature” to the first 63 blocks, but we use Diskpart, or Diskpar to offset the disk space the Clariion Writes to of the remaining space on the first disk. When Cache writes out to disk now, it will begin writing out to the first block on the second disk in the Raid Group, thereby giving the full 128 blocks/64 KB chunk that the Clariion hopes to write out to one physical disk.

The problem with all of this is that this offset or alignment needs to set on a Window’s Disk/LUN before any data is written to the LUN. Once there is data on the LUN, this cannot be done without destroying the existing LUN/data. The only way to now fix this problem is to create a new LUN on the Clariion, assign it to the host, set the offset/alignment, and do a host-based copy/migration. Again, a Clariion LUN Migration is a block for block LUN copy/move. All you are doing with a LUN Migration is moving the problem to a new location on the Clariion.

Windows has two utilities from the Command prompt that can be run to set the offset/alignment, Diskpar and Diskpart.

Diskpar is used for Window’s systems running Windows 2000, or 2003, not using at least Service Pack 1. Diskpar can be downloaded as part of the Resource Kit, and requires through its command line interface that the offset be equal to 128. Diskpar sets the offset in blocks, Since the Clariion formats the disks in 128 blocks, the Clariion will now offset writing to the LUN to block number 128, which is the first block on the second disk.

Diskpart is for Windows Systems running Windows 2003, service pack 1 and up. Diskpart sets the alignment in KiloBytes. Since the Clariion formats the disk in 64 KB, the Clariion will now align the writing to the LUN in 64 KB Chunks, or the first full 64 KB chunk, which is the second physical disk in the Raid Group.

This is also an issue with Linux servers, as an offset will need to set as well. Here again, the number to use is 128, because fdisk uses the number of blocks, not KiloBytes.

LUN Migration

The process of a LUN Migration has been available in Navisphere as of Flare Code or Release 16. The LUN Migration is a move of a LUN within a Clariion from one location to another location. It is a two step process. First it is a block by block copy of a “Source LUN” to its new location “Destination LUN”. After the copy is complete, it then moves the “Source” LUNs location to its new place in the Clariion.

The Process of the Migration.

Again, this type of LUN Migration is an internal move of a LUN, not like a SANCopy where a Data Migration occurs between a Clariion and another storage device. In the illustration above, we are showing that we are moving Exchange off of the Vault drives onto Raid Group 10 on another Enclosure in the Clariion. We will first discuss the process of the Migration, and then the Rules of the Migration.

1. Create a Destination LUN. This is going to be the Source LUN’s new location in the Clariion on the disks. The Destination LUN is a LUN which can be on a different Raid Group, on a different BUS, on a different Enclosure. The reason for a LUN Migration might be an instance where we may want to offload a LUN from a busy Raid Group for performance issues. Or, we want to move a LUN from Fibre Drives to ATA Drives. This we will discuss in the RULES portion.

2. Start the Migration from the Source LUN. From the LUN in Navisphere, we simply right-click and select Migrate. Navisphere gives us a window that displays the current information about the Source LUN, and a selection window of the Destination LUN. Once we select the Destination LUN and click Apply, the migration begins. The migration process is actually a two step process. It is a copy first, then a move. Once the migration begins, it is a block for block copy from the Source LUN (Original Location) to the Destination LUN (New Location). This is important to know because the Source LUN does not have to be offline while this process is running. The host will continue to read and write to the Source LUN, which will write to Cache, then Cache writing out to the disk. Because it is a copy, any new write to the source lun will also write to the destination lun. At any time during this process, you may cancel the Migration if the wrong LUN was selected, or to wait until a later time. A priority level is also available to speed up or slow down the process.

3. Migration Completes. When the migration completes, the Source LUN will then MOVE to it’s new location in the Clariion. Again, there is nothing that needs to be done from the host, as it is still the same LUN as it was to begin with, just in a new space on the Clariion. The host doesn’t even know that the LUN is on a Clariion. It thinks the LUN is a local disk. The Destination LUN ID that you give a LUN when creating, will disappear. To the Clariion, that LUN never existed. The Source LUN will occupy the space of the Destination LUN, taking with it the same LUN ID, SP Ownership, and host connectivity. The only things that may or may not change based on your selection of the Destination might be the Raid type, Raid Group, size of the LUN, or Drive Type. The original space that the Source LUN once occupied is going to show as FREE Space in Navisphere on the Clariion. If you were to look at the Raid Group where the Source LUN used to live, under the Partitions tab, you will see the space the original LUN occupied as a Free. The Source LUN is still in the same Storage Group, assigned to the Host as it was before.

Migration Rules

The rules of a Migration as illustrated above are as follows.

The Destination LUN can be:

1. Equal to in size or larger. You can migrate a LUN to a LUN that is the exact same block count size, or to a LUN that is larger in size, so long as the host has the ability to see the additional space once the migration has completed. Windows would need a rescan, reboot of the disks to see the additional space, then using Diskpart, extend the Volume on the host. A host that doesn’t haven’t the ability to extend a volume, would need a Volume Manager software to grow a filesystem, etc.

2. The same or a different drive type. A destination LUN can be on the same type of drives as the source, or a different type of drive. For instance, you can migrate a LUN from Fibre Drives to ATA Drives when the Source LUN no longer needs the faster type drives. This is a LUN to LUN copy/move, so again, disk types will not stop a migration from happening, although it may slow the process from completing.

3. The same or a different raid type. Again, because it is a LUN to LUN copy, raid types don’t matter. You can move a LUN from Raid 1_0 to Raid 5 and reclaim some of the space on the Raid 1_0 disks. Or find that Raid 1_0 better suits your needs for performance and redundancy than Raid 5.

4. A Regular LUN or MetaLUN. The destination LUN only has to be equal in size, so whether it is a regular LUN on a 5 disk Raid 5 group or a Striped MetaLUN spread across multiple enclosures, buses, raid groups for performance is completely up to you.

However, the Destination LUN cannot be:

1. Smaller in size. There is no way on a Clariion to shrink a LUN to allow a user to reclaim space that is not being used.

2. A SnapView, MirrorView, or SanCopy LUN. Because these LUNs are being used by the Clariion to replicate data for local recoveries, replicate data to another Clariion for Disaster Recovery, or to move the data to/from another storage device, they are not available as a Destination LUN.

3. In a Storage Group. If a LUN is in a Storage Group, it is believed to belong to a Host. Therefore, the Clariion will not let you write over a LUN that potentially belongs to another host.

MetaLUNs

The purpose of a MetaLUN is that a Clariion can grow the size of a LUN on the ‘fly’. Let’s say that a host is running out of space on a LUN. From Navisphere, we can “Expand” a LUN by adding more LUNs to the LUN that the host has access to. To the host, we are not adding more LUNs. All the host is going to see is that the LUN has grown in size. We will explain later how to make space available to the host.

There are two types of MetaLUNs, Concatenated and Striped. Each has their advantages and disadvantages, but the end result which ever you use, is that you are growing, “expanding” a LUN.

A Concatenated MetaLUN is advantageous because it allows a LUN to be “grown” quickly and the space made available to the host rather quickly as well. The other advantage is that the Component LUNs that are added to the LUN assigned to the Host can be of a different RAID type and of a different size.

The host writes to Cache on the Storage Processor, the Storage Processor then flushes out to the disk. With a Concatenated MetaLUN, the Clariion only writes to one LUN at a time. The Clariion is going to write to LUN 6 first. Once the Clariion fills LUN 6 with data, it then begins writing to the next LUN in the MetaLUN, which is LUN 23. The Clariion will continue writing to LUN 23 until it is full, then write to LUN 73. Because of this writing process, there is no performance gain. The Clariion is still only writing to one LUN at a time.

A Striped MetaLUN is advantageous because if setup properly could enhance performance as well as protection. Let’s look first at how the MetaLUN is setup and written to, and how performance can be gained. With the Striped MetaLUN, the Clariion writes to all LUNs that make up the MetaLUN, not just one at a time. The advantage of this is more spindles/disks. The Clariion will stripe the data across all of the LUNs in the MetaLUN, and if the LUNs are on different Raid Groups, on different Buses, this will allow the application to be striped across fifteen (15) disks, and in the example above, three back-end buses of the Clariion. The workload of the application is being spread out across the back-end of the Clariion, thereby possibly increasing speed. As illustrated above, the first Data Stripe (Data Stripe 1) that the Clariion writes out to disk will go across the five disks on Raid Group 5 where LUN 6 lives. The next stripe of data (Data Stripe 2), is striped across the five disks that make up RAID Group 10 where LUN23 lives. And finally, the third stripe of data (Data Stripe 3) is striped across the five disks that make up Raid Group 20 where LUN 73 lives. And then the Clariion starts the process all over again with LUN6, then LUN 23, then LUN 73. This gives the application 15 disks to be spread across, and three buses.

As for data protection, this would be similar to building a 15 disk raid group. The problem with a 15 disk raid group is that if one disk where to fail, it would take a considerable amount of time to rebuild the failed disk from the other 14 disks. Also, if there were two disks to fail in this raid group, and it was RAID 5, data would be lost. In the drawing above, each of the LUNs is on a different RAID group. That would mean that we could lose a disk in RAID Group 5, RAID Group 10, and RAID Group 20 at the same time, and still have access to the data. The other advantage of this configuration is that the rebuilds are occurring within each individual RAID Group. Rebuilding from four disks is going to be much faster than the 14 disks in a fifteen disk RAID Group.

The disadvantage of using a Striped MetaLUN is that it takes time to create. When a component LUN is added to the MetaLUN, the Clariion must restripe the data across the existing LUN(s) and the new LUN. This takes time and resources of the Clariion. There may be a performance impact while a Striped MetaLUN is re-striping the data. Also, the space is not available to the host until the MetaLUN has completed re-striping the data.

Access Logix

Access Logix, often referred to as ‘LUN Masking’, is the Clariion term for:

1. Assigning LUNs to a particular Host

2. Making sure that hosts cannot see every LUN in the Clariion

Let’s talk about making sure that every host cannot see every LUN in the Clariion first.

Access Logix is an enabler on the Clariion that allows hosts to connect to the Clariion, but not have the ability to just go out and take ownership of every LUN. Think of this situation. You have ten Window’s Hosts attached to the Clariion, five Solaris Hosts, eight HP Hosts, etc… If all of the hosts were attached to the Clariion (zoning), and there was no such thing as Access Logix, every host could potentially see every LUN after a rescan or 17 reboots by Window’s. Probably not a good thing to have more than one host writing to a LUN at a time, let alone different Operating Systems writing to the same LUNs.

Now, in order for a host to see a LUN, a few things must be done first in Navisphere.

1. For a Host, a Storage Group must be created. In the illustration above, the ‘Storage Group’ is like a bucket.

2. We have to Connect the host to the Storage Group

3. Finally, we have to add the LUNs to the Host’s Storage Group we want the host to see.

From the illustration above, let’s start with the Windows Host on the far left side. We created a Storage Group for the Windows Host. You can name the Storage Group whatever you want in Navisphere. It would make sense to name the Storage Group the same as the Host name. Second, we connected the host to the Storage Group. Finally, we added LUNs to the Storage Group. Now, the host has the ability to see the LUNs, after a rescan, or a reboot.

However, in the Storage Group, when the LUNs are added to the Storage Group, there is a column on the bottom right-side of the Storage Group window that is labeled Host ID. You will notice that as the LUNs are placed into the Storage Group, Navisphere gives each LUN a Host ID number. The host ID number starts at 0, and continues to 255. We can place up to 256 LUNs into a Storage Group. The reason for this, is that the Host has no idea that the LUN is on a Clariion. The host believes that the LUN is a Local Disk. For the host, this is fine. In Windows, the host is going to rescan, and pick up the LUNs as the next available disk. In the example above, the Windows Host picks up LUNs 6 and 23, but to the host, after a rescan/reboot, the host is going to see the LUNs as Disk 4 and Disk 5, which we can now initialize, add a drive letter, format, create the partition, and make the LUN visible through the host.

In the case of the Solaris Host’s Storage Group, when we added the LUNs to the Storage Group, we changed LUN 9s host id to 9, and LUN 15s host id to 15. This allows the Solaris host to see the Clariion LUN 9 as c_t_d 9, and LUN 15 as c_t_d 15. If we hadn’t changed the Host ID number for the LUNs however, Navisphere would have assigned LUN 9 with the Host ID of 0, and LUN 15 with the Host ID of 1. Then the host would see LUN 9 as c_t_d 0 and LUN 15 as c_t_d 15.

The last drawing is an example of a Clustered environment. The blue server is the Active Node of the cluster, and the orange server is the Standby/Passive Node of the cluster. In this example, we created a Storage Group in Navisphere for each host in the Cluster. Into the Active Node Storage Group, we place LUN 8. LUN 8 also went into the Passive Node Storage Group. A LUN can belong to multiple storage groups. The reason for this, is if we only placed LUN 8 in to the Active Node Storage Group, not into the Passive Node Storage Group, and the Cluster failed over to the Passive Node for some reason, there would be no LUN to see. A host can only see what is in it’s storage group. That is why LUN 8 is in both Storage Groups.

Now, if this is not a Clustered Environment, this brings up another problem. The Clariion does not limit who has access, or read/write privileges to a LUN. When a LUN is assigned to a Storage Group, the LUN belongs to the host. If we assign a LUN out to two hosts, with no Cluster setup, we are giving simultaneous access of a LUN to two different servers. This means that each server would assume ownership of the LUN, and constantly be overwriting each other’s data.

We also added LUN 73 to the Active Node Storage Group, and LUN 74 to the Passive Node Storage Group. This allows each server to see LUN 8 for failover purposes, but LUN 73 only belonging to the Active Node Host, and LUN 74 belonging to the Passive Node Host. If the cluster fails over to the Passive Node, the Passive Node will see LUN 8 and LUN 74, not LUN 73 because it is not in the Storage Group.

Notice that LUN 28 is in the Clariion, but not assigned to anyone at the time. No host has the ability to access LUN 28.

Clariion Disk Format

Disk Format

The Clariion Formats the disks in Blocks. Each Block written out to the disk is 520 bytes in size. Of the 520 bytes, 512 bytes is used to store the actual DATA written to the block. The remaining 8 bytes per block is used by the Clariion to store System Information, such as a Timestamp, Parity Information, Checksum Data.

Element Size – The Element Size of a disk is determined when a LUN is bound to the RAID Group. In previous versions of Navisphere, a user could configure the Element Size from 4 blocks per disk 256 blocks per disk. Now, the default Element Size in Navisphere is 128. This means that the Clariion will write 128 blocks of data to one physical disk in the RAID Group before moving to the next disk in the RAID Group and write another 128 blocks to that disk, so on and so on.

Chunk Size – The Chunk Size is the amount of Data the Clariion writes to a physical disk at a time. The Chunk Size is calculated by multiplying the Element Size by the amount of Data per block written by the Clariion.

128 blocks x 512 bytes of Data per block = 65,536 bytes of Data per Disk. That is equal to 64 KB. So, the Chunk Size, the amount of Data the Clariion writes to a single disk, before writing to the next disk in the RAID Group is 64 KB.

LUNs

As stated in the Host Configuration Slide, a LUN is the disk space that is created on the Clariion. The LUN is the space that is presented to the host. The host will see the LUN as a “Local Disk.”

In Windows, the Clariion LUN will show up in Disk Manager is Drive #, which the Windows Administrator can now format, partition, assign a Drive Letter, etc…

In UNIX, the Clariion LUN will show up as a c_t_d_ address, which the UNIX Administrator can now mount.

A LUN is owned by a single Storage Processor at a time. When creating a LUN, you assign the LUN to a Storage Processor, SPA, SPB or let the Clariion choose by selecting AUTO. The Auto option lets the Clariion assign the next LUN to the Storage Processor with the fewest number of LUNs.

The Properties/Settings of LUN during creation/binding are:

1. Selecting which RAID Group the LUN will be bound to.

2. If it is the first LUN created on a RAID Group, the first LUN will set the RAID Type for the entire RAID Group. Therefore, when creating/binding the first LUN on a RAID Group, you can select the RAID Type.

3. Select a LUN Id or number for the LUN.

4. Specify a REBUILD PRIORITY for the LUN in the event of a Hot Spare replacing a failed disk.

5. Specify a VERIFY PRIORITY for the LUN to determine the speed in which the Clariion runs a “SNIFFER” in the background to scrub the disks.

6. Enable or Disable Read and Write Cache at the LUN level. An example might be to disable Read/Write Cache for a LUN that is given to a Development Server. This ensures that the Development LUNs will not use the Cache that is needed for Production Data.

7. Enable Auto Assign. By default this box is unchecked in Navisphere. That is because you will have some sort of Host Based Software that will manage the trespassing and failing back of a LUN.

8. Number of LUNs to Bind. You can bind up to 128 LUNs on a single RAID Group.

9. SP Ownership. You can select if you want your LUN(s) to belong to SP A, SP B, or the AUTO option in which the Clariion decides LUN ownership based on the Storage Processor with the fewest number of LUNs.

10. LUN Size. You specify the size of a LUN by entering the numbers, and selecting MB (MegaBytes), GB (GigaBytes), TB (TeraBytes), or Block Count to specify the number of blocks a LUN will be. This is critical for SnapView Clones, and MirrorView Secondary LUNs.

The amount of LUNs a Clariion can support is going to be Clariion specific.

CX 300 – 512 LUNs

CX3-20 – 1024 LUNs

CX3-80 – 2048 LUNs

Order of Disks in RAID Group for RAID 1_0.

When creating a RAID 1_0 Raid Group, it is important to know and understand the order of the drives as they are put into the RAID Group will absolutely make a difference in the Performance and Protection of that RAID Group. If left to the Clariion, it will simply choose the next disks in the order in which is sees the disks to create the RAID Group. However, this may not be the best way to configure a RAID 1_0 RAID Group. Navisphere will take the next disks available, which are usually right next to one another in the same enclosure.

In a RAID 1_0 Group, we want the RAID Group to span multiple enclosures as illustrated above. The reason for this is as we can see, the Data Disks will be on Bus 1_Enclosure 0, and the Mirrored Data Disks will be on Bus 2_Enclosure 0. The advantage of creating the RAID Group this way is that we place the Data and Mirrors on two separate enclosures. In the event of an enclosure failure, the other enclosure could still be alive and maintaining access to the data or the mirrored data. The second advantage is Performance. Performance could be gained through this configuration because you are spreading the workload of the application across two different buses on the back of the Clariion.

Notice the order in which the disks were placed into the RAID 1_0 Group. In order to for the disks to be entered into the RAID Group in this order, they must be manually entered into the RAID Group this way via Navisphere or the Command Line.

The first disk into the RAID Group receives Data Block 1.

The second disk into the RAID Group receives the Mirror of Data Block 1.

The third disk into the RAID Group receives Data Block 2.

The fourth disk into the RAID Group receives the Mirror of Data Block 2.

The fifth disk into the RAID Group received Data Block 3.

The sixth disk into the RAID Group receives the Mirror of Data Block 3.

If we let the Clariion choose these disks in its particular order, it would select them:

First disk – 1_0_0 (Data Block 1)

Second disk – 1_0_1 (Mirror of Data Block 1)

Third disk – 1_0_2 (Data Block 2)

Fourth disk – 2_0_0 (Mirror of Data Block 2)

Fifth disk – 2_0_1 (Data Block 3)

Sixth disk – 2_0_2 (Mirror of Data Block 3)

This defeats the purpose of having the Mirrored Data on a different enclosure than the Data Disks.

RAID GROUPS and RAID Types

The above slide illustrates the concept of creating a RAID Group and the supported RAID types of the Clariions.

RAID Groups

The concept of a RAID Group on a Clariion is to group together a number of disks on the Clariion into one big group. Let’s say that we need a 1 TB LUN. The disks we have a 200 GB in size. We would have to group together five (5) disks to get to the 1 TB size needed for the LUN. I know we haven’t taken into account for parity and what the RAW capacity of a drive is, but that is just a very basic idea of what we mean by a RAID Group. RAID Groups also allow you to configure the Clariion in a way so that you will know what LUNs, Applications, etc…live on what set of disks in the back of the Clariion. For instance, you wouldn’t want an Oracle Database LUN on the same RAID Group (Disks) as a SQL Database running on the same Clariion. This allows you to create a RAID Group of a # of disks for the Oracle Database, and another RAID Group of a different set of disks for the SQL Database.

RAID Types

Above are the supported RAID types of the Clariion.

RAID 0 – Striping Data with NO Data Protection. The Clariions Cache will write the data out to disk in blocks (chunks) that we will discuss later. For RAID 0, the Clariion writes/stripes the data across all of the disks in the RAID Group. This is fantastic for performance, but if one of the disks fail in the RAID 0 Group, then the data will be lost because there is no protection of that data (i.e. mirroring, parity).

RAID 1 – Mirroring. The Clariion will write the Data out to the first disk in the RAID Group, and write the exact data to another disk in that RAID 1 Group. This is great in terms of data protection because if you were to lose the data disk, the mirror would have the exact copy of the data disk, allowing the user to access the disk.

RAID 1_0 – Mirroring and Striping Data. This is the best of both worlds if set up properly. This type of RAID Group will allow the Clariion to stripe data and mirror the data onto other disks. However, the illustration above of RAID 1_0, is not the best way of configuring that type of RAID Group. The next slide will go into detail as to why this isn’t the best method of configuring RAID 1_0.

RAID 3 – Striping Data with a Dedicated Parity Drive. This type of RAID Group allows the Clariion to stripe data the first X number of disks in the RAID Group, and dedicate the last disk in the RAID Group for Parity of the data stripe. In the event of a single drive failure in this RAID Group, the failed disk can be rebuilt from the remaining disks in the RAID Group.

RAID 5 – Striping Data with Distributed Parity. RAID type 5 allows the Clariion to distribute the Parity information to rebuild a failed disk across the disks that make up the RAID Group. As in RAID 3, in the event of a single drive failure in this RAID Group, the failed disk can be rebuilt from the remaining disks in the RAID Group.

RAID 6 – Striping Data with Double Parity. This is new to Clariion world starting in Flare Code 26 of Navisphere. The simplest explanation of RAID 6 we can use for RAID 6 is the RAID Group uses striping, such as RAID 5, with double the parity. This allows a RAID 6 RAID Group to be able to have two drive failures in the RAID Group, while maintaining access to the LUNs.

HOT SPARE – A Dedicated Single Disk that Acts as a Failed Disk. A Hot Spare is created as a single disk RAID Group, and is bound/created as a HOT SPARE in Navisphere. The purpose of this disk is to act as the failed disk in the event of a drive failure. Once a disk is set as a HOT SPARE, it is always a HOT SPARE, even after the failed disk is replaced. In the slide above, we list the steps of a HOT SPARE taking over in the event of a disk failure in the Clariion.

1. A disk fails – a disk fails in a RAID Group somewhere in the back of the Clariion.

2. Hot Spare is Invoked – a Clariion dedicated HOT SPARE acts as the failed disk in Navisphere. It will assume the identity of the failed disk’s Bus_Enclosure_Disk Address.

3. Data is REBUILT Completely onto the Hot Spare from the other disks in the RAID Group – The Clariion begins to recalculate and rebuild the failed disk onto the Hot Spare from the other disks in the RAID Group, whether it be copying from the MIRRORed copy of the disk, or through parity and data calculations of a RAID 3 or RAID 5 Group.

4. Disk is replaced – Somewhere throughout the process, the failed drive is replaced.

5. Data is Copied back to new disk – The data is then copied back to the new disk that was replaced. This will take place automatically, and will not begin until the failed disk is completely rebuilt onto the Hot Spare.

6. Hot Spare is back to a Hot Spare – Once the data is written from the Hot Spare back to the failed disk, the Hot Spare goes back to being a Hot Spare waiting for another disk failure.

Hot Spares are going to be size and drive type specific.

Size. The Hot Spare must be at least the same size as the largest size disk in the Clariion. A Hot Spare will replace a drive that is the same size or a smaller size drive. The Clariion does not allow multiple smaller Hot Spares replace a failed disk.

Drive Type Specific. If your Clariion has a mixture of Drive Types, such as Fibre and S.ATA disks, you will need Hot Spares of those particular Drive Types. A Fibre Hot Spare will not replace a failed S.ATA disk and vice versa.

Hot Spares are not assigned to any particular RAID Group. They are used by the Clariion in the event of any failure of that Drive Type. The recommendation for Hot Spares is one (1) Hot Spare for every thirty (30) disks.

There are multiple ways to create a RAID Group. One is via the Navisphere GUI, and the other is through the Command Line Interface. In later slides we will list the commands to create a RAID Group.

Vault Drives

All Clariions have Vault Drives. They are the first five (5) disks in all Clariions. Disks 0_0_0 through 0_0_4. The Vault drives on the Clariion are going to contain some internal information that is pre-configured before you start putting data on the Clariion. The diagram will show what information is stored on the Vault Disks.

The Vault.

The vault is a ‘save area’ across the first five disks to store write cache from the Storage Processors in the event of a Power Failure to the Clariion, or a Storage Processor Failure. The goal here is to place write cache on disk before the Clariion powers off, therefore ensuring that you don’t lose the data that was committed to the Clariion and acknowledged to the host. The Clariions have the Standby Power Supplies that will keep the Storage Processors running as well as the first enclosure of disks in the event of a power failure. If there is a Storage Processor Failure, the Clariion will go into a ‘panic’ mode and fear that it may lose the other Storage Processor. To ensure that it does not lose write cache data, the Clariion will also dump write cache to the Vault Drives.

The PSM Lun.

The Persistent Storage Manager Lun stores the configuration of the Clariion. Such as Disks, Raid Groups, Luns, Access Logix information, SnapView configuration, MirrorView and SanCopy configuration as well. When this LUN was first introduced on the Clariions back on the FC4700s, it used to appear in Navisphere under the Unowned Luns container as Lun 223-PSM Lun. Users have not been able to see it in Navisphere for awhile. However, you can grab the information of the Array’s Configuration by executing the following command.

naviseccli -h 10.127.35.42 arrayconfig -capture -output c:\arrayconfig.xml -format XML -schema clariion

Example of Information retrieved from the File:

For a Disk:

/CLAR:Disk

CLAR:Disk type="Category"

CLAR:Bus type="Property"1/CLAR:Bus

CLAR:Enclosure type="Property"0/CLAR:Enclosure

CLAR:Slot type="Property"12/CLAR:Slot

CLAR:State type="Property"3/CLAR:State

CLAR:UserCapacityInBlocks type="Property"274845/CLAR:UserCapacityInBlocks

For a LUN:

/CLAR:LUN

CLAR:LUN type="Category"

CLAR:Name type="Property"LUN 23/CLAR:Name

CLAR:WWN type="Property"60:06:01:60:06:C4:1F:00:B1:51:C4:1B:B3:A2:DC:11/CLAR:WWN

CLAR:Number type="Property"6142/CLAR:Number

CLAR:RAIDType type="Property"1/CLAR:RAIDType

CLAR:RAIDGroupID type="Property"13/CLAR:RAIDGroupID

CLAR:State type="Property"Bound/CLAR:State

CLAR:CurrentOwner type="Property"1/CLAR:CurrentOwner

CLAR:DefaultOwner type="Property”2/CLAR:DefaultOwner

CLAR:Capacity type="Property"2097152/CLAR:Capacity

Flare Database LUN.

The Flare Database LUN will contain the Flare Code that is running on the Clariion. I like to say that it is the application that runs on the Storage Processors that allows the SPs to create the Raid Groups, Bind the LUNs, setup Access Logix, SnapView, MirrorView, SanCopy, etc…

Operating System.

The Operating System of the Storage Processors is stored to the first five drives of the Clariion.

Now, please understand that this information is NOT in any way shape or form laid out this way across these disks. We are only seeing that this information is built onto these first five drives of the Clariion. This information does take up disk space as well. The amount of disk space that it takes up per drive is going to depend on what Flare Code the Clariion is running. Clariions running Flare Code 19 and lower, will lose approximately 6 GB of space per disk. Clariions running Flare Code 24 and up, will lose approximately 33 GB of space per disk. So, on a 300 GB fibre drive, the actual raw capacity of the drive is 268.4 GB. Also, you would subtract another 33 GB per disk for this Vault/PSM LUN/Flare Database LUN/Operating System Information. That would leave you with about 235 GB per disk on the first five disks.

General Commands for Navisphere CLI

Physical Container-Front End Ports Speeds

naviseccli –h 10.124.23.128 port –list -sfpstate

naviseccli –h 10.124.23.128 –set sp a –portid 0 2

naviseccli –h 10.124.23.128 backendbus –get –speeds 0

SP Reboot and Shutdown GUI

naviseccli –h 10.124.23.128 rebootsp

naviseccli –h 10.124.23.128 resetandhold

Disk Summary

naviseccli –h 10.124.23.128 getdisk

naviseccli –h 10.124.23.128 getdisk 0_0_9 (Bus_Enclosure_Disk - specific disk)

Storage System Properties- Cache Tab

naviseccli –h 10.124.23.128 getcache

naviseccli –h 10.124.23.128 setcache –wc 0 –rca 0 –rcb 0 (to disable Write and Read Cache)

naviseccli –h 10.124.23.128 setcache –p 4 –l 50 –h 70 (Set Page Size to 4 KB, Low WaterMark to 50%, and High WaterMark to 70%)

naviseccli –h 10.124.23.128 setcache –wc 1 –rca 1 –rcb 1 (to enable Write and Read Cache)

Storage System Properties- Memory Tab

naviseccli –h 10.124.23.128 setcache –wsz 2500 –rsza 100 –rszb 100

naviseccli –h 10.124.23.128 setcache –wsz 3072 –rsza 3656 –rszb 3656 (maximum amount of cache for CX3-80)

Creating a RAID Group

naviseccli –h 10.124.23.128 createrg 0 1_0_0 1_0_ 1 1_0_2 1_0_3 1_0_4 –rm no –pri med (same Enclosure)

-rm (remove/destroy Raid Group after the last LUN is unbound for the Raid Group) -pri (priority/rate of expansion/defragmentation of the Raid Group)

naviseccli –h 10.124.23.128 createrg 1 2_0_0 3_0_0 2_0_1 3_0_1 2_0_2 3_0_2 -raidtype r1_0 (for RAID 1_0 across enclosures)

RAID Group Properties - General

naviseccli –h 10.124.23.128 getrg 0

RAID Group Properties - Disks

naviseccli –h 10.124.23.128 getrg 0 –disks

Binding a LUN

naviseccli –h 10.124.23.128 bind r5 0 –rg 0 –rc 1 –wc 1 –sp a –sq gb –cap 10

bind raid type (r0, r1, r1_0, r3, r5, r6) -rg (raid group) -rc / -wc (read and write cache) -sp (storage processor) -sq (size qualifier - mb, gb, tb, bc (block count) -cap (size of the LUN)

LUN Properties

naviseccli –h 10.124.23.128 getlun 0

naviseccli –h 10.124.23.128 chglun –l 0 –name Exchange_Log_Lun_0

RAID Group Properties - Partitions

naviseccli –h 10.124.23.128 getrg 0 –lunlist

Destroying a RAID Group

naviseccli –h 10.124.23.128 removerg 0

Creating a Storage Group

navicli –h 10.127.24.128 storagegroup –create –gname ProductionHost

Storage Group Properties - LUNs with Host ID

navicli –h 10.127.24.128 storagegroup –addhlu –gname ProductionHost –alu 6 –hlu 6

navicli –h 10.127.24.128 storagegroup –addhlu –gname ProductionHost –alu 23 –hlu 23

Storage Group Properties - Hosts

navicli –h 10.127.24.128 storagegroup –connecthost –host ProductionHost –gname ProductionHost

Destroying Storage Groups

navicli –h 10.127.24.128 storagegroup –destroy –gname ProductionHost

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2010-04-07T00:41:00.001-07:00

Retrospect 8.0 Desktop 3U Mac Mac 8.0

ACTIVE DIRECTORY – DNS – FSMO – GROUP POLICY

2008-03-07T18:35:00.001-08:00

ACTIVE DIRECTORY – DNS – FSMO – GROUP POLICY

What Is Active Directory?
Active Directory consists of a series of components that constitute both its logical structure and its physical structure. It provides a way for organizations to centrally manage and store their user objects, computer objects, group membership, and define security boundaries in a logical database structure.
Purpose of Active Directory
Active Directory stores information about users, computers, and network resources and makes the resources accessible to users and applications. It provides a consistent way to name, describe, locate, access, manage, and secure information about these resources

Functions of Active Directory

Active Directory provides the following functions:
● Centralizes control of network resourcesBy centralizing control of resources such as servers, shared files, and printers, only authorized users can access resources in Active Directory.
● Centralizes and decentralizes resource managementAdministrators have Centralized Administration with the ability to delegate administration of subsets of the network to a limited number of individuals giving them greater granularity in resource management.
● Store objects securely in a logical structureActive Directory stores all of the resources as objects in a secure, hierarchical logical structure.
● Optimizes network trafficThe physical structure of Active Directory enables you to use network bandwidth more efficiently. For example, it ensures that, when users log on to the network, the authentication authority that is nearest to the user, authenticates them reducing the amount of network traffic.

Sites within Active Directory

Sites are defined as groups of well-connected computers. When you establish sites, domain controllers within a single site communicate frequently. This communication minimizes the latency within the site; that is, the time required for a change that is made on one domain controller to be replicated to other domain controllers. You create sites to optimize the use of bandwidth between domain controllers that are in different locations

Operations Master Roles

When a change is made to a domain, the change is replicated across all of the domain controllers in the domain. Some changes, such as those made to the schema, are replicated across all of the domains in the forest. This replication is called multimaster replication.
During multimaster replication, a replication conflict can occur if originating updates are performed concurrently on the same object attribute on two domain controllers. To avoid replication conflicts, Active Directory uses single master replication, which designates one domain controller as the only domain controller on which certain directory changes can be made. This way, changes cannot occur at different places in the network at the same time. Active Directory uses single master replication for important changes, such as the addition of a new domain or a change to the forest-wide schema.
Operations that use single-master replication are arranged together in specific roles in a forest or domain. These roles are called operations master roles. For each operations master role, only the domain controller that holds that role can make the associated directory changes. The domain controller that is responsible for a particular role is called an operations master for that role. Active Directory stores information about which domain controller holds a specific role.

Forest-wide Roles

Forest-wide roles are unique to a forest, forest-wide roles are:
● Schema masterControls all updates to the schema. The schema contains the master list of object classes and attributes that are used to create all Active Directory objects, such as users, computers, and printers.
● Domain naming masterControls the addition or removal of domains in the forest. When you add a new domain to the forest, only the domain controller that holds the domain naming master role can add the new domain.
There is only one schema master and one domain naming master in the entire forest.
Domain-wide Roles

Domain-wide roles are unique to each domain in a forest, the domain-wide roles are:
● Primary domain controller emulator (PDC) Acts as a Windows NT PDC to support any backup domain controllers (BDCs) running Microsoft Windows® NT within a mixed-mode domain. This type of domain has domain controllers that run Windows NT 4.0. The PDC emulator is the first domain controller that you create in a new domain.
● Relative identifier master (RID)When a new object is created, the domain controller creates a new security principal that represents the object and assigns the object a unique security identifier (SID). This SID consists of a domain SID, which is the same for all security principals created in the domain, and a RID, which is unique for each security principal created in the domain. The RID master allocates blocks of RIDs to each domain controller in the domain. The domain controller then assigns a RID to objects that are created from its allocated block of RIDs.
● Infrastructure masterwhen objects are moved from one domain to another, the infrastructure master updates object references in its domain that point to the object in the other domain. The object reference contains the object’s globally unique identifier (GUID), distinguished name, and a SID. Active Directory periodically updates the distinguished name and the SID on the object reference to reflect changes made to the actual object, such as moves within and between domains and the deletion of the object.
The global catalog contains:
● The attributes that are most frequently used in queries, such as a user’s first name, last name, and logon name.
● The information that is necessary to determine the location of any object in the directory.
● The access permissions for each object and attribute that is stored in the global catalog. If you search for an object that you do not have the appropriate permissions to view, the object will not appear in the search results. Access permissions ensure that users can find only objects to which they have been assigned access.
A global catalog server is a domain controller that, in addition to its full, writable domain directory partition replica, also stores a partial, read-only replica of all other domain directory partitions in the forest. Taking a user object as an example, it would by default have many different attributes such as first name, last name, phone number, and many more. The GC will by default only store the most common of those attributes that would be used in search operations (such as a user’s first and last names, or login name, for example). The partial attributes that it has for that object would be enough to allow a search for that object to be able to locate the full replica of the object in active directory. This allows searches done against a local GC, and reduces network traffic over the WAN in an attempt to locate objects somewhere else in the network.
Domain Controllers always contain the full attribute list for objects belonging to their domain. If the Domain Controller is also a GC, it will also contain a partial replica of objects from all other domains in the forest.

Active Directory uses DNS as the name resolution service to identify domains and domain host computers during processes such as logging on to the network.
Similar to the way a Windows NT 4.0 client will query WINS for a NetBIOS DOMAIN[1B] record to locate a PDC, or a NetBIOS DOMAIN[1C] record for domain controllers, a Windows 2000, 2003, or Windows XP client can query DNS to find a domain controller by looking for SRV records.

Integration of DNS and Active Directory

The integration of DNS and Active Directory is essential because a client computer in a Windows 2000 network must be able to locate a domain controller so that users can log on to a domain or use the services that Active Directory provides. Clients locate domain controllers and services by using A resource records and SRV records. The A resource record contains the FQDN and IP address for the domain controller. The SRV record contains the FQDN of the domain controller and the name of the service that the domain controller provides.

What Are Active Directory Integrated Zones?
One benefit of integrating DNS and Active Directory is the ability to integrate DNS zones into an Active Directory database. A zone is a portion of the domain namespace that has a logical grouping of resource records, which allows zone transfers of these records to operate as one unit.
Active Directory Integrated Zones
Microsoft DNS servers store information that is used to resolve host names to IP addresses and IP addresses to host names in a database file that has the extension .dns for each zone.
Active Directory integrated zones are primary zones that are stored as objects in the Active Directory database. If zone objects are stored in an Active Directory domain partition, they are replicated to all domain controllers in the domain.

What Are DNS Zones?

A zone starts as a storage database for a single DNS domain name. If other domains are added below the domain used to create the zone, these domains can either be part of the same zone or belong to another zone. Once a subdomain is added, it can then either be:
● Managed and included as part of the original zone records, or
● Delegated away to another zone created to support the subdomain
Types of Zones
5
There are two types of zones, forward lookup and reverse lookup. Forward lookup zones contain information needed to resolve names within the DNS domain. They must include SOA and NS records and can include any type of resource record except the PTR resource record. Reverse lookup zones contain information needed to perform reverse lookups. They usually include SOA, NS, PTR, and CNAME records.
With most queries, the client supplies a name and requests the IP address that corresponds to that name. This type of query is typically described as a forward lookup. Active Directory requires forward lookup zones.
However, what if a client already has a computer's IP address and wants to determine the DNS name for the computer? This is important for programs that implement security based on the connecting FQDN, and is used for TCP/IP network troubleshooting. The DNS standard provides for this possibility through reverse lookups.
Once you have installed Active Directory, you have two options for storing your zones when operating the DNS server at the new domain controller:
Standard Zone
Zones stored this way are located in .dns text files that are stored in the %SystemRoot%\System32\Dns folder on each computer operating a DNS server. Zone file names correspond to the name you choose for the zone when creating it, such as Example.microsoft.com.dns if the zone name was example.microsoft.com.
This type offers the choice of using either a Standard Primary zone or a Standard Secondary zone.
Standard Primary Zone
For standard primary-type zones, only a single DNS server can host and load the master copy of the zone. If you create a zone and keep it as a standard primary zone, no additional primary servers for the zone are permitted. Only one server is allowed to accept dynamic updates, also known as DDNS, and process zone changes. The standard primary model implies a single point of failure.
Standard Secondary Zone
A secondary name server gets the data for its zones from another name server (either a primary name server or another secondary name server) for that zone across the network. The data in a Secondary zone is Read only, and updated information must come from additional zone transfers. The process of obtaining this zone information (i.e., the database file) across the network is referred to as a zone transfer. Zone transfers occur over TCP port 53.
Secondary servers can provide a means to offload DNS query traffic in areas of the network where a zone is heavily queried and used. Additionally, if a primary server is down, a secondary server can provide some name resolution in the zone until the primary server is available.
Note A Standard Primary zone will not replicate its information to any other DNS servers, but may allow zone transfers to Secondary zones. Win2003 also supports stub zones. A secondary or stub zone cannot be hosted on a DNS server that hosts a primary zone for the same domain name.

Directory-integrated Zone
Zones stored this way are located in the Active Directory tree under the domain object container. Each directory-integrated zone is stored in a dnsZone container object identified by the name you choose for the zone when creating it. Active Directory integrated zones will replicate this information to other domain controllers in that domain.
Note If DNS is running on a Windows 2000 server that is not a domain controller, it will not be able to use an Active Directory integrated zones, or replicate with other domain controllers since it does not have Active Directory installed.
DNS Records

After you create a zone, additional resource records need to be added to it. The most common resource records (RRs) to be added are:
Table 5. Record Types
Name
Description
Host (A)
For mapping a DNS domain name to an IP address used by a computer.
Alias (CNAME)
For mapping an alias DNS domain name to another primary or canonical name.
Mail Exchanger (MX)
For mapping a DNS domain, name to the name of a computer that exchanges or forwards mail.
Pointer (PTR)
For mapping a reverse DNS domain name based on the IP address of a computer that points to the forward DNS domain name of that computer.
Service location (SRV)
For mapping a DNS domain name to a specified list of DNS host computers that offer a specific type of service, such as Active Directory domain controllers.

Other resource records as needed.

Q1. What does the logical component of the Active Directory structure include?

■ Objects:-Resources are stored in the Active Directory as objects.

Sub category: object class

An object is really just a collection of attributes. A user object, for example, is made up of attributes such as name, password, phone number, group membership, and so on. The attributes that make up an object are defined by an object class. The user class, for example, specifies the attributes that make up the user object.

The Active Directory Schema:-

The classes and the attributes that they define are collectively referred to as the Active Directory Schema—in database terms, a schema is the structure of the tables and fields and how they are related to one another. You can think of the Active Directory Schema as a collection of data (object classes) that defines how the real data of the directory (the attributes of an object) is organized and stored

■ Domains

The basic organizational structure of the Windows Server 2003 networking model is the domain. A domain represents an administrative boundary. The computers, users, and other objects within a domain share a common security database.

■ Trees

Multiple domains are organized into a hierarchical structure called a tree. Actually, even if you have only one domain in your organization, you still have a tree. The first domain you create in a tree is called the root domain. The next domain that you add becomes a child domain of that root. This expandability of domains makes it possible to have many domains in a tree. Figure 1-1 shows an example of a tree. Microsoft.com was the first domain created in Active Directory in this example and is therefore the root domain.

Microsoft.com

sales.microsoft.com

RND.Microsoft.com

West.Microsoft.com

East.Microsoft.com

Figure 1-1 A tree is a hierarchical organization of multiple domains.
All domains in a tree share a common schema and a contiguous namespace. In the example shown in Figure 1-1, all of the domains in the tree under the microsoft.com root domain share the namespace microsoft.com. Using a single tree is fine if your organization is confined within a single DNS namespace. However, for organizations that use multiple DNS namespaces, your model must be able to expand outside the boundaries of a single tree. This is where the forest comes in.

■ Forest

A forest is a group of one or more domain trees that do not form a contiguous namespace but may share a common schema and global catalog. There is always at least one forest on a network, and it is created when the first Active Directory–enabled computer (domain controller) on a network is installed.

This first domain in a forest, called the forest root domain, is special because it holds the schema and controls domain naming for the entire forest. It cannot be removed from the forest without removing the entire forest itself. Also, no other domain can ever be created above the forest root domain in the forest domain hierarchy.

Figure 1-2 shows an example of a forest with two trees. Each tree in the forest has its own namespace. In the figure, microsoft.com is one tree and contoso.com is a second tree. Both are in a forest named microsoft.com (after the first domain created)

Root domain of microsoft.com forest & tree

Root domain of Contoso.com forest

Microsoft.com

sales.microsoft.com

RND.Microsoft.com

West.Microsoft.com

East.Microsoft.com

Contoso.com

West.contoso.com

East.contoso.com

Figure 1-2 Trees in a forest share the same schema, but not the same namespace.

A forest is the outermost boundary of Active Directory; the directory cannot be larger than the forest. However, you can create multiple forests and then create trust relationships between specific domains in those forests; this would let you grant access to resources and accounts that are outside of a particular forest.

■Organizational Units

Organizational Units (OUs) provide a way to create administrative boundaries within a domain. Primarily, this allows you to delegate administrative tasks within the domain.

OUs serve as containers into which the resources of a domain can be placed. You can then assign administrative permissions on the OU itself. Typically, the structure of OUs follows an organization’s business or functional structure. For example, a relatively small organization with a single domain might create separate OUs for departments within the organization.

Q2. What does the physical structure of active directory contain?

Physical structures include domain controllers and sites.

Q3.What is nesting?

The creation of an OU inside another OU.

IMP: - once you go beyond about 12 OUs deep in a nesting structure, you start running into significant performance issues.

Q4. What is trust relationship and how many types of trust relationship is there in exchange 2003?

Since domains represent security boundaries, special mechanisms called trust relationships allow objects in one domain (called the trusted domain) to access resources in another domain (called the trusting domain).

Windows Server 2003 supports six types of trust relationships:

■ Parent and child trusts
■ Tree-root trusts
■ External trusts
■ Shortcut trusts
■ Realm trusts
■ Forest trusts

Q5. What is a site?

A Windows Server 2003 site is a group of domain controllers that exist on one or more IP subnets (see Lesson 3 for more on this) and are connected by a fast, reliable network connection. Fast means connections of at least 1Mbps. In other words, a site usually follows the boundaries of a local area network (LAN). If different LANs on the network are connected by a wide area network (WAN), you’ll likely create one site for each LAN.

Q6. What is the use of site?

Sites are primarily used to control replication traffic. Domain controllers within a site are pretty much free to replicate changes to the Active Directory database whenever changes are made. Domain controllers in different sites compress the replication traffic and operate based on a defined schedule, both of which are intended to cut down on network traffic.

More specifically, sites are used to control the following:

■ Workstation logon traffic
■ Replication traffic
■ Distributed File System (DFS)

Distributed File System (DFS) is a server component that provides a unified naming convention for folders and files stored on different servers on a network. DFS lets you create a single logical hierarchy for folders and files that is consistent on a network, regardless of where on the network those items are actually stored. Files represented in the DFS might be stored in multiple locations on the network, so it makes sense that Active Directory should be able to direct users to the closest physical location of the data they need. To this end, DFS uses site information to direct a client to the server that is hosting the requested data within the site. If DFS does not find a copy of the data within the same site as the client, DFS uses the site information in Active Directory to determine which file server that has DFS shared data is closest to the client.

■ File Replication Service (FRS)

Every domain controller has a built-in collection of folders named SYSVOL (for System Volume). The SYSVOL folders provide a default Active Directory location for files that must be replicated throughout a domain. You can use SYSVOL to replicate Group Policy Objects, startup and shutdown scripts, and logon and logoff scripts. A Windows Server 2003 service named File Replication Service (FRS) is responsible for replicating files in the SYSVOL folders between domain controllers. FRS uses site boundaries to govern the replication of items in the SYSVOL folders.

Q7. What are the objects a site contains?

Sites contain only two types of objects. The first type is the domain controllers contained in the site. The second type of object is the site links configured to connect the site to other sites.

Q8.What is a Site link?

Within a site, replication happens automatically. For replication to occur between sites, you must establish a link between the sites. There are two components to this link: the actual physical connection between the sites (usually a WAN link) and a site link object. The site link object is created within Active Directory and determines the protocol used for transferring replication traffic (Internet Protocol [IP] or Simple Mail Transfer Protocol [SMTP]). The site link object also governs when replication is scheduled to occur.

Q9. Explain Replication in Active directory?

Windows Server 2003 uses a replication model called multimaster replication, in which all replicas of the Active Directory database are considered equal masters. You can make changes to the database on any domain controller and the changes will be replicated to other domain controllers in the domain.

Domain controllers in the same site replicate on the basis of notification. When changes are made on a domain controller, it notifies its replication partners (the other domain controllers in the site); the partners then request the changes and replication occurs. Because of the high-speed, low-cost connections assumed within a site, replication occurs as needed rather than according to a schedule.

You should create additional sites when you need to control how replication traffic occurs over slower WAN links. For example, suppose you have a number of domain controllers on your main LAN and a few domain controllers on a LAN at a branch location. Those two LANs are connected to one another with a slow (256K) WAN link. You would want replication traffic to occur as needed between the domain controllers on each LAN, but you would want to control traffic across the WAN link to prevent it from affecting higher priority network traffic. To address this situation, you would set up two sites— one site that contained all the domain controllers on the main LAN and one site that contained all the domain controllers on the remote LAN.

Q10. What are the different types of replication?

Single site (called intrasite replication)
Replication between sites (called intersite replication).

■ Intrasite Replication Intrasite replication sends replication traffic in an uncompressed format. This is because of the assumption that all domain controllers within the site are connected by high-bandwidth links. Not only is the traffic uncompressed, but replication occurs according to a change notification mechanism. This means that if changes are made in the domain, those changes are quickly replicated to the other domain controllers.

■ Intersite Replication Intersite replication sends all data compressed. This shows an appreciation for the fact that the traffic will probably be going across slower WAN links (as opposed to the LAN connectivity intrasite replication assumes), but it increases the server load because compression/decompression is added to the processing requirements. In addition to the compression, the replication can be scheduled for times that are more appropriate to your organization. For example, you may decide to allow replication only during slower times of the day. Of course, this delay in replication (based on the schedule) can cause inconsistency between servers in different sites.

Q11. What is LDAP?

LDAP, Lightweight Directory Access Protocol, is an Internet protocol that email and other programs use to look up information from a server.

An LDAP-aware directory service (such as Active Directory) indexes all the attributes of all the objects stored in the directory and publishes them. LDAP-aware clients can query the server in a wide variety of ways.

Q12.What types of naming convention active directory uses?

Active Directory supports several types of names for the different formats that can accessActive Directory.
These names include:

■ Relative Distinguished Names

The relative distinguished name (RDN) of an object identifies an object uniquely, but only within its parent container. Thus the name uniquely identifies the object relative to the other objects within the same container. In the example

CN=wjglenn,CN=Users,DC=contoso,DC=com,

the relative distinguished name of the object is CN=wjglenn. The relative distinguished name of the parent organizational unit is Users. For most objects, the relative distinguished name of an object is the same as that object’s Common Name attribute. Active Directory creates the relative distinguished name automatically, based on information provided when the object is created. Active Directory does not allow two objects with the same relative distinguished name to exist in the same parent container.

The notations used in the relative distinguished name (and in the distinguished name discussed in the next section) use special notations called LDAP attribute tags to identify each part of the name. The three attribute tags used include:

■ DC The Domain Component (DC) tag identifies part of the DNS name of the domain, such as COM or ORG.
■ OU The Organizational Unit (OU) tag identifies an organizational unit container.
■ CN The Common Name (CN) tag identifies the common name configured for an Active Directory object.

■ Distinguished Names

Each object in the directory has a distinguished name (DN) that is globally unique and identifies not only the object itself, but also where the object resides in the overall object hierarchy. You can think of the distinguished name as the relative distinguished name of an object concatenated with the relative distinguished names of all parent containers that make up the path to the object.

An example of a typical distinguished name would be:

CN=wjglenn,CN=Users,DC=contoso,DC=com.

This distinguished name would indicate that the user object wjglenn is in the Users container, which in turn is located in the contoso.com domain. If the wjglenn object is moved to another container, its DN will change to reflect its new position in the hierarchy. Distinguished names are guaranteed to be unique in the forest, similar to the way that a fully qualified domain name uniquely identifies an object’s placement in a DNS hierarchy. You cannot have two objects with the same distinguished name.

■ User Principal Names

The user principal name that is generated for each object is in the form username@ domain_name. Users can log on with their user principal name, and an administrator can define suffixes for user principal names if desired. User principal names should be unique, but Active Directory does not enforce this requirement. It’s best, however, to formulate a naming convention that avoids duplicate user principal names.

■ Canonical Names

An object’s canonical name is used in much the same way as the distinguished name— it just uses a different syntax. The same distinguished name presented in the preceding section would have the canonical name:

contoso.com/Users/wjglenn.

As you can see, there are two primary differences in the syntax of distinguished names and canonical names. The first difference is that the canonical name presents the root of the path first and works downward toward the object name. The second difference is that the canonical name does not use the LDAP attribute tags (e.g., CN and DC).

Q13. What is multimaster replication?

Active Directory follows the multimaster replication which every replica of the Active Directory partition held on every domain is considered an equal master. Updates can be made to objects on any domain controller, and those updates are then replicated to other domain controllers.

Q14.Which two operations master roles should be available when new security principals are being created and named?

Domain naming master and the relative ID master

Q15. What are different types of groups?

■ Security groups Security groups are used to group domain users into a single administrative unit. Security groups can be assigned permissions and can also be used as e-mail distribution lists. Users placed into a group inherit the permissions assigned to the group for as long as they remain members of that group. Windows itself uses only security groups.

■ Distribution groups These are used for nonsecurity purposes by applications other than Windows. One of the primary uses is within an e-mail

As with user accounts, there are both local and domain-level groups. Local groups are stored in a local computer’s security database and are intended to control resource access on that computer. Domain groups are stored in Active Directory and let you gather users and control resource access in a domain and on domain controllers.

Q16. What is a group scope and what are the different types of group scopes?

Group scopes determine where in the Active Directory forest a group is accessible and what objects can be placed into the group. Windows Server 2003 includes three group scopes: global, domain local, and universal.

■ Global groups are used to gather users that have similar permissions requirements. Global groups have the following characteristics:

1. Global groups can contain user and computer accounts only from the domain in which the global group is created.
2. When the domain functional level is set to Windows 2000 native or Windows Server 2003 (i.e., the domain contains only Windows 2000 or 2003 servers), global groups can also contain other global groups from the local domain.
3. Global groups can be assigned permissions or be added to local groups in any domain in a forest.

■ Domain local groups exist on domain controllers and are used to control access to resources located on domain controllers in the local domain (for member servers and workstations, you use local groups on those systems instead). Domain local groups share the following characteristics:

1. Domain local groups can contain users and global groups from any domain in a forest no matter what functional level is enabled.
2. When the domain functional level is set to Windows 2000 native or Windows Server 2003, domain local groups can also contain other domain local groups and universal groups.

■ Universal groups are normally used to assign permissions to related resources in multiple domains. Universal groups share the following characteristics:

1. Universal groups are available only when the forest functional level is set to Windows 2000 native or Windows Server 2003.
2. Universal groups exist outside the boundaries of any particular domain and are managed by Global Catalog servers.
3. Universal groups are used to assign permissions to related resources in multiple domains.
4. Universal groups can contain users, global groups, and other universal groups from any domain in a forest.
5. You can grant permissions for a universal group to any resource in any domain.

Q17. What are the items that groups of different scopes can contain in mixed and native mode domains?

Q18. What is group nesting?

Placing of one group in another is called as group nesting

For example, suppose you had juniorlevel administrators in four different geographic locations, as shown in Figure 4-10. You could create a separate group for each location (named something like Dallas Junior
Admins). Then, you could create a single group named Junior Admins and make each of the location-based groups a member of the main group. This approach would allow you to set permissions on a single group and have those permissions flow down to the members, yet still be able to subdivide the junior administrators by location.

Q19. How many characters does a group name contain?

64

Q20. Is site part of the Active Directory namespace?

NO: - When a user browses the logical namespace, computers and users are grouped into domains and OUs without reference to sites. However, site names are used in the Domain Name System (DNS) records, so sites must be given valid DNS names.

Q21. What is DFS?

The Distributed File System is used to build a hierarchical view of multiple file servers and shares on the network. Instead of having to think of a specific machine name for each set of files, the user will only have to remember one name; which will be the 'key' to a list of shares found on multiple servers on the network. Think of it as the home of all file shares with links that point to one or more servers that actually host those shares.

DFS has the capability of routing a client to the closest available file server by using Active Directory site metrics. It can also be installed on a cluster for even better performance and reliability.
Understanding the DFS TerminologyIt is important to understand the new concepts that are part of DFS. Below is an definition of each of them.
Dfs root: You can think of this as a share that is visible on the network, and in this share you can have additional files and folders.
Dfs link: A link is another share somewhere on the network that goes under the root. When a user opens this link they will be redirected to a shared folder.
Dfs target (or replica): This can be referred to as either a root or a link. If you have two identical shares, normally stored on different servers, you can group them together as Dfs Targets under the same link.The image below shows the actual folder structure of what the user sees when using DFS and load balancing.
Figure 1: The actual folder structure of DFS and load balancing
Windows 2003 offers a revamped version of the Distributed File System found in Windows 2000, which has been improved to better performance and add additional fault tolerance, load balancing and reduced use of network bandwidth. It also comes with a powerful set of command-line scripting tools which can be used to make administrative backup and restoration tasks of the DFS namespaces easier. The client windows operating system consists of a DFS client which provides additional features as well as caching.

Q22. What are the types of replication in DFS?
There are two types of replication: * Automatic - which is only available for Domain DFS * Manual - which is available for stand alone, DFS and requires all files to be replicated manually.
Q23. Which service is responsible for replicating files in SYSVOL folder?

File Replication Service (FRS)

Q24. What all can a site topology owner do?

The site topology owner is the name given to the administrator (or administrators) that oversee the site
topology. The owner is responsible for making any necessary changes to the site as the physical network grows and changes. The site topology owner’s responsibilities include:

■ Making changes to the site topology based on changes to the physical network topology.
■ Tracking subnetting information for the network. This includes IP addresses, subnet masks, and the locations of the subnets.
■ Monitoring network connectivity and setting the costs for links between sites.

Q1. What is DNS.
DNS provides name registration and name to address resolution capabilities. And DNS drastically lowers the need to remember numeric IP addresses when accessing hosts on the Internet or any other TCP/IP-based network.
Before DNS, the practice of mapping friendly host or computer names to IP addresses was handled via host files. Host files are easy to understand. These are static ASCII text files that simply map a host name to an IP address in a table-like format. Windows ships with a HOSTS file in the \winnt\system32\drivers\etc subdirectory
The fundamental problem with the host files was that these files were labor intensive. A host file is manually modified, and it is typically centrally administrated.
The DNS system consists of three components: DNS data (called resource records), servers (called name servers), and Internet protocols for fetching data from the servers.

Q2. Which are the four generally accepted naming conventions?
NetBIOS Name (for instance, SPRINGERS01)TCP/IP Address (121.133.2.44)Host Name (Abbey)Media Access Control (MAC)—this is the network adapter hardware address

Q3. How DNS really works
DNS uses a client/server model in which the DNS server maintains a static database of domain names mapped to IP addresses. The DNS client, known as the resolver, perform queries against the DNS servers. The bottom line? DNS resolves domain names to IP address using these steps

Step 1. A client (or “resolver”) passes its request to its local name server. For example, the URL term www.idgbooks.com typed into Internet Explorer is passed to the DNS server identified in the client TCP/IP configuration. This DNS server is known as the local name server.

Step 2. If, as often happens, the local name server is unable to resolve the request, other name servers are queried so that the resolver may be satisfied.

Step 3. If all else fails, the request is passed to more and more, higher-level name servers until the query resolution process starts with far-right term (for instance, com) or at the top of the DNS tree with root name servers

Below is the Steps explained with the help of a chart.
Figure 8-5: How DNS works

Q4. Which are the major records in DNS?
1. Host or Address Records (A):- map the name of a machine to its numeric IP address. In clearer terms, this record states the hostname and IP address of a certain machine. Have three fields: Host Name, Domain, Host IP Address.
E.g.:- eric.foobarbaz.com. IN A 36.36.1.6
It is possible to map more than one IP address to a given hostname. This often happens for people who run a firewall and have two thernet cards in one machine. All you must do is add a second A record, with every column the same save for the IP address.
2. Aliases or Canonical Name Records (CNAME)
“CNAME” records simply allow a machine to be known by more than one hostname. There must always be an A record for the machine before aliases can be added. The host name of a machine that is stated in an A record is called the canonical, or official name of the machine. Other records should point to the canonical name. Here is an example of a CNAME:
www.foobarbaz.com. IN CNAME eric.foobarbaz.com.
You can see the similarities to the previous record. Records always read from left to right, with the subject to be queried about on the left and the answer to the query on the right. A machine can have an unlimited number of CNAME aliases. A new record must be entered for each alias.
You can add A or CNAME records for the service name pointing to the machines you want to load balance.
3. Mail Exchange Records (MX)
MX” records are far more important than they sound. They allow all mail for a domain to be routed to one host. This is exceedingly useful – it abates the load on your internal hosts since they do not have to route incoming mail, and it allows your mail to be sent to any address in your domain even if that particular address does not have a computer associated with it. For example, we have a mail server running on the fictitious machine eric.foobarbaz.com. For convenience sake, however, we want our email address to be “user@foobarbaz.com” rather than “user@eric.foobarbaz.com”. This is accomplished by the record shown below:
foobarbaz.com. IN MX 10 eric.foobarbaz.com.
The column on the far left signifies the address that you want to use as an Internet email address. The next two entries have been explained thoroughly in previous records. The next column, the number “10”, is different from the normal DNS record format. It is a signifier of priority. Often larger systems will have backup mail servers, perhaps more than one. Obviously, you will only want the backups receiving mail if something goes wrong with the primary mail server. You can indicate this with your MX records. A lower number in an MX record means a higher priority, and mail will be sent to the server with the lowest number (the lowest possible being 0). If something happens so that this server becomes unreachable, the computer delivering the mail will attempt every other server listed in the DNS tables, in order of priority.
Obviously, you can have as many MX records as you would like. It is also a good idea to include an MX record even if you are having mail sent directly to a machine with an A record. Some sendmail programs only look for MX records.
It is also possible to include wildcards in MX records. If you have a domain where your users each have their own machine running mail clients on them, mail could be sent directly to each machine. Rather than clutter your DNS entry, you can add an MX record like this one:
*.foobarbaz.com. IN MX 10 eric.foobarbaz.com.
This would make any mail set to any individual workstation in the foobarbaz.com domain go through the server eric.foobarbaz.com.
One should use caution with wildcards; specific records will be given precedence over ones containing wildcards.

4. Pointer Records (PTR)
Although there are different ways to set up PTR records, we will be explaining only the most frequently used method, called “in-addr.arpa”.
In-addr.arpa PTR records are the exact inverse of A records. They allow your machine to be recognized by its IP address. Resolving a machine in this fashion is called a “reverse lookup”. It is becoming more and more common that a machine will do a reverse lookup on your machine before allowing you to access a service (such as a World Wide Web page). Reverse lookups are a good security measure, verifying that your machine is exactly who it claims to be. In-addr.arpa records look as such:
6.1.36.36.in-addr.arpa. IN PTR eric.foobarbaz.com.
As you can see from the example for the A record in the beginning of this document, the record simply has the IP address in reverse for the host name in the last column.
A note for those who run their own name servers: although Allegiance Internet is capable of pulling zones from your name server, we cannot pull the inverse zones (these in-addr.arpa records) unless you have been assigned a full class C network. If you would like us to put PTR records in our name servers for you, you will have to fill out the online web form on the support.allegianceinternet.com page.
5. Name Server Records (NS)
NS records are imperative to functioning DNS entries. They are very simple; they merely state the authoritative name servers for the given domain. There must be at least two NS records in every DNS entry. NS records look like this:
foobarbaz.com. IN NS draven.foobarbaz.com.
There also must be an A record in your DNS for each machine you enter as A NAME server in your domain.
If Allegiance Internet is doing primary and secondary names service, we will set up these records for you automatically, with “nse.algx.net” and “nsf.algx.net” as your two authoritative name servers.
6. Start Of Authority Records (SOA)
The “SOA” record is the most crucial record in a DNS entry. It conveys more information than all the other records combined. This record is called the start of authority because it denotes the DNS entry as the official source of information for its domain. Here is an example of a SOA record, then each part of it will be explained:
foobarbaz.com. IN SOA draven.foobarbaz.com. hostmaster.foobarbaz.com. (

1996111901 ; Serial
10800 ; Refresh
3600 ; Retry
3600000 ; Expire
86400 ) ; Minimum
The first column contains the domain for which this record begins authority for. The next two entries should look familiar. The “draven.foobarbaz.com” entry is the primary name server for the domain. The last entry on this row is actually an email address, if you substituted a “@” for the first “.”. There should always be a viable contact address in the SOA record.
The next entries are a little more unusual then what we have become used to. The serial number is a record of how often this DNS entry has been updated. Every time a change is made to the entry, the serial number must be incremented. Other name servers that pull information for a zone from the primary only pull the zone if the serial number on the primary name server’s entry is higher than the serial number on it’s entry. In this way the name servers for a domain are able to update themselves. A recommended way of using your serial number is the YYYYMMDDNN format shown above, where the NN is the number of times that day the DNS has been changed.
Also, a note for Allegiance Internet customers who run their own name servers: even if the serial number is incremented, you should still fill out the web form and use the comment box when you make changes asking us to pull the new zones.
All the rest of the numbers in the record are measurements of time, in seconds. The “refresh” number stands for how often secondary name servers should check the primary for a change in the serial number. “Retry” is how long a secondary server should wait before trying to reconnect to primary server if the connection was refused. “Expire” is how long the secondary server should use its current entry if it is unable to perform a refresh, and “minimum” is how long other name servers should cache, or save, this entry.
There can only be one SOA record per domain. Like NS records, Allegiance Internet sets up this record for you if you are not running your own name server.
Quick Summary of the major records in DNS

Record Type
Definition
Host (A)
Maps host name to IP address in a DNS zone. Has three fields: Domain, Host Name, Host IP Address.
Aliases (CNAME)
Canonical name resource record that creates an alias for a host name. CNAME records are typically used to hide implementation details from clients. Fields include: Domain, Alias Name, For Host DNS Name.
Nameservers (NS)
Identifies the DNS name servers in the DNS domain. NS records appear in all DNS zones and reverse zones. Fields include: Domain, Name Server DNS Name.
Pointer (PTR)
Maps IP address to host name in a DNS reverse zone. Fields include: IP Address, Host DNS Name.
Mail Exchange (MX)
Specifies a mail exchange server for a DNS domain name. Note that the term “exchange” does not refer to Microsoft Exchange, a BackOffice e-mail application. However, to connect Microsoft Exchange to the Internet via the Internet Mail Server (IMS), the MX record must be correctly configured by your ISP.A mail exchange server is a host that will either process or forward mail for the DNS domain name. Processing the mail means either delivering it to the addressee or passing it to a different type of mail transport. Forwarding the mail means sending it to its final destination server, sending it using Simple Mail Transfer Protocol to another mail server that is closer to the final destination, or queuing it for a specified amount of time.Fields include: Domain, Host Name (Optional), Mail Exchange Server DNS Name, Preference Number.

Q5.What is a DNS zone
A zone is simply a contiguous section of the DNS namespace. Records for a zone are stored and managed together. Often, subdomains are split into several zones to make manageability easier. For example, support.microsoft.com and msdn.microsoft.com are separate zones, where support and msdn are subdomains within the Microsoft.com domain.
Q6. Name the two Zones in DNS?
DNS servers can contain primary and secondary zones. A primary zone is a copy of a zone where updates can be made, while a secondary zone is a copy of a primary zone. For fault tolerance purposes and load balancing, a domain may have several DNS servers that respond to requests for the same information.
The entries within a zone give the DNS server the information it needs to satisfy requests from other computers or DNS servers.
Q7. How many SOA record does each zone contain?
Each zone will have one SOA record. This records contains many miscellaneous settings for the zone, such as who is responsible for the zone, refresh interval settings, TTL (Time To Live) settings, and a serial number (incremented with every update).
Q8. Short summary of the records in DNS.
The NS records are used to point to additional DNS servers. The PTR record is used for reverse lookups (IP to name). CNAME records are used to give a host multiple names. MX records are used when configuring a domain for email.

Q9. What is an AD-integrated zone?

AD-integrated zones store the zone data in Active Directory and use the same replication process used to replicate other data between domain controllers. The one catch with AD-integrated zones is that the DNS server must also be a domain controller. Overloading DNS server responsibilities on your domain controllers may not be something you want to do if you plan on supporting a large volume of DNS requests.

Q10.What is a STUB zone?

A stub zone is a copy of a zone that contains only those resource records necessary to identify the authoritative Domain Name System (DNS) servers for that zone. A stub zone is used to resolve names between separate DNS namespaces. This type of resolution may be necessary when a corporate merger requires that the DNS servers for two separate DNS namespaces resolve names for clients in both namespaces.
The master servers for a stub zone are one or more DNS servers authoritative for the child zone, usually the DNS server hosting the primary zone for the delegated domain name.

Q11. What does a stub zone consists of?

A stub zone consists of:

•
The start of authority (SOA) resource record, name server (NS) resource records, and the glue A resource records for the delegated zone.
•
The IP address of one or more master servers that can be used to update the stub zone.

Q12. How the resolution in a stub zone takes place?

When a DNS client performs a recursive query operation on a DNS server hosting a stub zone, the DNS server uses the resource records in the stub zone to resolve the query. The DNS server sends an iterative query to the authoritative DNS servers specified in the NS resource records of the stub zone as if it were using NS resource records in its cache. If the DNS server cannot find the authoritative DNS servers in its stub zone, the DNS server hosting the stub zone attempts standard recursion using its root hints.

The DNS server will store the resource records it receives from the authoritative DNS servers listed in a stub zone in its cache, but it will not store these resource records in the stub zone itself; only the SOA, NS, and glue A resource records returned in response to the query are stored in the stub zone. The resource records stored in the cache are cached according to the Time-to-Live (TTL) value in each resource record. The SOA, NS, and glue A resource records, which are not written to cache, expire according to the expire interval specified in the stub zone's SOA record, which is created during the creation of the stub zone and updated during transfers to the stub zone from the original, primary zone.

If the query was an iterative query, the DNS server returns a referral containing the servers specified in the stub zone.

Q 13.What is the benefits of Active Directory Integration?

For networks deploying DNS to support Active Directory, directory-integrated primary zones are strongly recommended and provide the following benefits:
* Multimaster update and enhanced security based on the capabilities of Active Directory

In a standard zone storage model, DNS updates are conducted based upon a single-master update model. In this model, a single authoritative DNS server for a zone is designated as the primary source for the zone.

This server maintains the master copy of the zone in a local file. With this model, the primary server for the zone represents a single fixed point of failure. If this server is not available, update requests from DNS clients are not processed for the zone.

With directory-integrated storage, dynamic updates to DNS are conducted based upon a multimaster update model.

In this model, any authoritative DNS server, such as a domain controller running a DNS server, is designated as a primary source for the zone. Because the master copy of the zone is maintained in the Active Directory database, which is fully replicated to all domain controllers, the zone can be updated by the DNS servers operating at any domain controller for the domain.

With the multimaster update model of Active Directory, any of the primary servers for the directory-integrated zone can process requests from DNS clients to update the zone as long as a domain controller is available and reachable on the network.

Also, when using directory-integrated zones, you can use access control list (ACL) editing to secure a dnsZone object container in the directory tree. This feature provides granulated access to either the zone or a specified RR in the zone.

For example, an ACL for a zone RR can be restricted so that dynamic updates are only allowed for a specified client computer or a secure group such as a domain administrators group. This security feature is not available with standard primary zones.

Note that when you change the zone type to be directory-integrated, the default for updating the zone changes to allow only secure updates. Also, while you may use ACLs on DNS-related Active Directory objects, ACLs may only be applied to the DNS client service.

* Directory replication is faster and more efficient than standard DNS replication.

Because Active Directory replication processing is performed on a per-property basis, only relevant changes are propagated. This allows less data to be used and submitted in updates for directory-stored zones.

Note: Only primary zones can be stored in the directory. A DNS server cannot store secondary zones in the directory. It must store them in standard text files. The multimaster replication model of Active Directory removes the need for secondary zones when all zones are stored in Active Directory.

Q14. What is Scavenging?

DNS scavenging is the process whereby resource records are automatically removed if they are not updated after a period of time. Typically, this applies to only resource records that were added via DDNS, but you can also scavenge manually added, also referred to as static, records. DNS scavenging is a recommended practice so that your DNS zones are automatically kept clean of stale resource records.

Q15. What is the default interval when DNS server will kick off the scavenging process?

The default value is 168 hours, which is equivalent to 7 days.

DNS Q&A corner
Q1. How do I use a load balancer with my name servers?
Ø Just wanted to ask a question about load balanced DNS servers> via an external network load balancing appliance (i.e - F5's Big IP,> Cisco's Content Switches/ Local Directors).> The main question being the configuration whether to use 2> Master/Primary Servers or is it wiser to use 1 Primary and 1> Secondary? The reason is that I feel there are two configurations> that could be setup. One in which only the resolvers query the> virtual IP address on the load balancing appliance or actually> configure your NS records to point to the Virtual Address so that all> queries, ie - both by local queries directly from local users and> also queries from external DNS servers. I've included a text> representation of the physical configuration. Have you ever> heard or architected such a configuration?

> VIP = 167.147.1.5> ------------------------------------>> Load Balancer Device > ------------------------------------> > > -----------------> > ---------------- -------------->> DNS 1 DNS 2 > ---------------- --------------> 1.1.1.1 1.1.1.2
There's usually not much need to design solutions like these, since mostname server implementations will automatically choose the name serverthat responds most quickly. In other words, if DNS 1 fails, remotename servers will automatically try DNS 2, and vice versa.
However, it can be useful for resolvers. In that case, you don't need toworry about NS records (since resolvers don't use them), just setting upa virtual IP address.
> Also, Is there any problems in running two Master/Primaries?
Just that you'd have to synchronize the zone data between the twomanually.

Q2. How does reverse mapping work?

Ø How can reverse lookup possibly work on the Internet - how can a local> resolver or ISP's Dns server find the pointer records please? E.g. I run> nslookup 161.114.1.206 & get a reply for a Compaq server> - how does it know where to look? Is there a giant reverse lookup zone in> the sky?Yes, actually, there is: in-addr.arpa.If a resolver needs to reverse map, say, 161.114.1.206 to a domain name, it first inverts the octets of the IP address and appends "in-addr.arpa." So, in this case, the IP address would become the domain name 206.1.114.161.in-addr.arpa.Then the resolver sends a query for PTR records attached to that domain name. If necessary, the resolution process starts at the root name servers. The root name servers refer the querier to the 161.in-addr.arpa name servers, run by an organization called ARIN, the American Registry for Internet Numbers. These name servers refer the querier to 1.114.161.in-addr.arpa name servers, run by Compaq. And, finally, these name servers map the IP address to inmail.compaq.com.

Q3. What are the pros and cons of running slaves versus caching-only name servers?
> Question: I am in the process of setting up dns servers in several locations for my > business. I have looked into having a primary master server running in my server > room and adding slave servers in the other areas. I then thought I could just > setup a primary and a single slave server and run caching only servers in the other > areas. What are the pros and cons of these two options, or should I run a slave > server in every location and still have a caching server with it? I just don't > know what the best way would be. Please help.
The main advantage of having slaves everywhere is that you have asource of your own zone data on each name server. So if you havea community of hosts near each slave that look up domain names inyour zones, the local name server can answer most of their queries.
On the other hand, administering slaves is a little more work thanadministering caching-only name servers, and a little greater burdenon the primary master name server.
Q4. Can I set a TTL on a specific record?
> Is it possible to setup ttl values for individual records in bind?
Sure. You specify explicit TTLs in a record's TTL field, between the ownerfield and the class field:
foo.example. 300 IN A 10.0.0.1
Q5. Can I use an A record instead of an MX record?
> I have a single machine running DNS mail and web for a domain> and I'm not sure that I have DNS setup properly. If the machine> that is running the mail is the name of the domain does there need> to be an MX record for mail?
Technically, no. Nearly all mailers will look up A records for adomain name in a mail destination if no MX records exist.
> If an MX record is not needed, how would you put in an MX> record for a backup mailserver.
You can't. If you want to use a backup mailer, you need to useMX records.
> www cname 192.168.0.1 > mail cname 192.168.0.1> pop cname 192.168.0.1> smtp cname 192.168.0.1
These CNAME records are all incorrect. CNAME records createan alias from one domain name to another, so the field after "CNAME"must contain a domain name, not an IP address. For example:www CNAME foo.example.
Q6. What are a zone's NS records used for?
> Could you elaborate a little bit on why do we need to put NS records for> the zone we are authoritative for ?> The parent name server handles these already. Is there any problem if our> own NS records have lower TTLs than the records from parent name server ?
That's a good question. The NS records from your zone data file are used for several things:
- Your name servers returns them in responses to queries, in the authority section of the DNS message. Moreover, the set of NS records that comes directly from your name server supersedes the set that a querier gets from your parent zone's name servers, so if the two sets are different, yours "wins."
- Your name servers use the NS records to determine where to send NOTIFY messages.
- Dynamic updaters determine where to send updates using the NS records, which they often get from the authoritative name servers.
Q7. Do slaves only communicate with their masters over TCP?
> When the slave zone checks in with the master zone for the serial number, is> all this traffic happening on TCP. For example, if you have acl's blocking> udp traffic but allowing tcp traffic will the transfer work or will it fail> due to the slaves inability to query for the SOA record on udp?
No. The refresh query (for the zone's SOA record) is usually done over UDP.
Q8. What's the largest number I can use in an MX record?

> Could you tell us the highest possible number we can use for the MX > preference ?Preference is an unsigned, 16-bit number, so the largest number youcan use is 65535.

Q9. Why are there only 13 root name servers?
> I'm very wondering why there are only 13 root servers on globally.> Some documents explain that one of the reason is technical limit on Domain > Name System (without any detailed explanation).> From my understanding, it seems that some limitation of NS record numbers> in DNS packet that specified by certain RFCs, or just Internet policy stuff.>> Which one is proper reason?
It's a technical limitation. UDP-based DNS messages can be up to 512 byteslong, and only 13 NS records and their corresponding A records will fit into a DNS message that size.
IMP information
http://www.menandmice.com/online_docs_and_faq/glossary/glossarytoc.htm
Q1.Which is the FIVE FSMO roles?
Schema Master
Forest Level
One per forest
Domain Naming Master
Forest Level
One per forest
PDC Emulator
Domain Level
One per domain
RID Master
Domain Level
One per domain
Infrastructure Master
Domain Level
One per domain
Q2. What are their functions?
1. Schema Master (Forest level)
The schema master FSMO role holder is the Domain Controller responsible for performing updates to the active directory schema. It contains the only writable copy of the AD schema. This DC is the only one that can process updates to the directory schema, and once the schema update is complete, it is replicated from the schema master to all other DCs in the forest. There is only one schema master in the forest.
2. Domain Naming Master (Forest level)
The domain naming master FSMO role holder is the DC responsible for making changes to the forest-wide domain name space of the directory. This DC is the only one that can add or remove a domain from the directory, and that is it's major purpose. It can also add or remove cross references to domains in external directories. There is only one domain naming master in the active directory or forest.
3. PDC Emulator (Domain level)
In a Windows 2000 domain, the PDC emulator server role performs the following functions: Password changes performed by other DCs in the domain are replicated preferentially to the PDC emulator first. Authentication failures that occur at a given DC in a domain because of an incorrect password are forwarded to the PDC emulator for validation before a bad password failure message is reported to the user. Account lockout is processed on the PDC emulator. Time synchronization for the domain.Group Policy changes are preferentially written to the PDC emulator.Additionally, if your domain is a mixed mode domain that contains Windows NT 4 BDCs, then the Windows 2000 domain controller, that is the PDC emulator, acts as a Windows NT 4 PDC to the BDCs.There is only one PDC emulator per domain.Note: Some consider the PDC emulator to only be relevant in a mixed mode domain. This is not true. Even after you have changed your domain to native mode (no more NT 4 domain controllers), the PDC emulator is still necessary for the reasons above.
4. RID Master (Domain level)
The RID master FSMO role holder is the single DC responsible for processing RID Pool requests from all DCs within a given domain. It is also responsible for removing an object from its domain and putting it in another domain during an object move.
When a DC creates a security principal object such as a user, group or computer account, it attaches a unique Security ID (SID) to the object. This SID consists of a domain SID (the same for all SIDs created in a domain), and a relative ID (RID) that makes the object unique in a domain.
Each Windows 2000 DC in a domain is allocated a pool of RIDs that it assigns to the security principals it creates. When a DC's allocated RID pool falls below a threshold, that DC issues a request for additional RIDs to the domain's RID master. The domain RID master responds to the request by retrieving RIDs from the domain's unallocated RID pool and assigns them to the pool of the requesting DC.There is one RID master per domain in a directory.
5. Infrastructure Master (Domain level)
The DC that holds the Infrastructure Master FSMO role is responsible for cross domain updates and lookups. When an object in one domain is referenced by another object in another domain, it represents the reference by the GUID, the SID (for references to security principals), and the distinguished name (DN) of the object being referenced. The Infrastructure role holder is the DC responsible for updating an object's SID and distinguished name in a cross-domain object reference.When a user in DomainA is added to a group in DomainB, then the Infrastructure master is involved. Likewise, if that user in DomainA, who has been added to a group in DomainB, then changes his username in DomainA, the Infrastructure master must update the group membership(s) in DomainB with the name change.There is only one Infrastructure master per domain.

Q3. What if a FSMO server fails?
Schema Master
No updates to the Active Directory schema will be possible. Since schema updates are rare (usually done by certain applications and possibly an Administrator adding an attribute to an object), then the malfunction of the server holding the Schema Master role will not pose a critical problem.
Domain Naming Master
The Domain Naming Master must be available when adding or removing a domain from the forest (i.e. running DCPROMO). If it is not, then the domain cannot be added or removed. It is also needed when promoting or demoting a server to/from a Domain Controller. Like the Schema Master, this functionality is only used on occasion and is not critical unless you are modifying your domain or forest structure.
PDC Emulator
The server holding the PDC emulator role will cause the most problems if it is unavailable. This would be most noticeable in a mixed mode domain where you are still running NT 4 BDCs and if you are using downlevel clients (NT and Win9x). Since the PDC emulator acts as a NT 4 PDC, then any actions that depend on the PDC would be affected (User Manager for Domains, Server Manager, changing passwords, browsing and BDC replication).In a native mode domain the failure of the PDC emulator isn't as critical because other domain controllers can assume most of the responsibilities of the PDC emulator.
RID Master
The RID Master provides RIDs for security principles (users, groups, computer accounts). The failure of this FSMO server would have little impact unless you are adding a very large number of users or groups.Each DC in the domain has a pool of RIDs already, and a problem would occur only if the DC you adding the users/groups on ran out of RIDs.
Infrastructure Master
This FSMO server is only relevant in a multi-domain environment. If you only have one domain, then the Infrastructure Master is irrelevant. Failure of this server in a multi-domain environment would be a problem if you are trying to add objects from one domain to another.

Q4. Where are these FSMO server roles found?
The first domain controller that is installed in a Windows 2000 domain, by default, holds all five of the FSMO server roles. Then, as more domain controllers are added to the domain, the FSMO roles can be moved to other domain controllers.
Q5. Can you Move FSMO roles?
Yes, moving a FSMO server role is a manual process, it does not happen automatically. But what if you only have one domain controller in your domain? That is fine. If you have only one domain controller in your organization then you have one forest, one domain, and of course the one domain controller. All 5 FSMO server roles will exist on that DC. There is no rule that says you have to have one server for each FSMO server role.

Q6. Where to place the FSMO roles?
Assuming you do have multiple domain controllers in your domain, there are some best practices to follow for placing FSMO server roles.
The Schema Master and Domain Naming Master should reside on the same server, and that machine should be a Global Catalog server. Since all three are, by default, on the first domain controller installed in a forest, then you can leave them as they are.Note: According to MS, the Domain Naming master needs to be on a Global Catalog Server. If you are going to separate the Domain Naming master and Schema master, just make sure they are both on Global Catalog servers.
IMP:- Why Infrastructure Master should not be on the same server that acts as a Global Catalog server?The Infrastructure Master should not be on the same server that acts as a Global Catalog server.The reason for this is the Global Catalog contains information about every object in the forest. When the Infrastructure Master, which is responsible for updating Active Directory information about cross domain object changes, needs information about objects not in it's domain, it contacts the Global Catalog server for this information. If they both reside on the same server, then the Infrastructure Master will never think there are changes to objects that reside in other domains because the Global Catalog will keep it constantly updated. This would result in the Infrastructure Master never replicating changes to other domain controllers in its domain.Note: In a single domain environment this is not an issue.Microsoft also recommends that the PDC Emulator and RID Master be on the same server. This is not mandatory like the Infrastructure Master and the Global Catalog server above, but is recommended. Also, since the PDC Emulator will receive more traffic than any other FSMO role holder, it should be on a server that can handle the load.It is also recommended that all FSMO role holders be direct replication partners and they have high bandwidth connections to one another as well as a Global Catalog server.
Q7.What permissions you should have in order to transfer a FSMO role?
Before you can transfer a role, you must have the appropriate permissions depending on which role you plan to transfer:
Schema Master
member of the Schema Admins group
Domain Naming Master
member of the Enterprise Admins group
PDC Emulator
member of the Domain Admins group and/or the Enterprise Admins group
RID Master
member of the Domain Admins group and/or the Enterprise Admins group
Infrastructure Master
member of the Domain Admins group and/or the Enterprise Admins group
FSMO TOOLS

Q8. Tools to find out what servers in your domain/forest hold what server roles?
1. Active Directory Users and Computers:- use this snap-in to find out where the domain level FSMO roles are located (PDC Emulator, RID Master, Infrastructure Master), and also to change the location of one or more of these 3 FSMO roles.Open Active Directory Users and Computers, right click on the domain you want to view the FSMO roles for and click "Operations Masters". A dialog box (below) will open with three tabs, one for each FSMO role. Click each tab to see what server that role resides on. To change the server roles, you must first connect to the domain controller you want to move it to. Do this by right clicking "Active Directory Users and Computers" at the top of the Active Directory Users and Computers snap-in and choose "Connect to Domain Controller". Once connected to the DC, go back into the Operations Masters dialog box, choose a role to move and click the Change button.When you do connect to another DC, you will notice the name of that DC will be in the field below the Change button (not in this graphic).
2. Active Directory Domains and Trusts - use this snap-in to find out where the Domain Naming Master FSMO role is and to change it's location.The process is the same as it is when viewing and changing the Domain level FSMO roles in Active Directory Users and Computers, except you use the Active Directory Domains and Trusts snap-in. Open Active Directory Domains and Trusts, right click "Active Directory Domains and Trusts" at the top of the tree, and choose "Operations Master". When you do, you will see the dialog box below. Changing the server that houses the Domain Naming Master requires that you first connect to the new domain controller, then click the Change button. You can connect to another domain controller by right clicking "Active Directory Domains and Trusts" at the top of the Active Directory Domains and Trusts snap-in and choosing "Connect to Domain Controller".
3. Active Directory Schema - this snap-in is used to view and change the Schema Master FSMO role. However... the Active Directory Schema snap-in is not part of the default Windows 2000 administrative tools or installation. You first have to install the Support Tools from the \Support directory on the Windows 2000 server CD or install the Windows 2000 Server Resource Kit. Once you install the support tools you can open up a blank Microsoft Management Console (start, run, mmc) and add the snap-in to the console. Once the snap-in is open, right click "Active Directory Schema" at the top of the tree and choose "Operations Masters". You will see the dialog box below. Changing the server the Schema Master resides on requires you first connect to another domain controller, and then click the Change button.
You can connect to another domain controller by right clicking "Active Directory Schema" at the top of the Active Directory Schema snap-in and choosing "Connect to Domain Controller
4.NetdomThe easiest and fastest way to find out what server holds what FSMO role is by using the Netdom command line utility. Like the Active Directory Schema snap-in, the Netdom utility is only available if you have installed the Support Tools from the Windows 2000 CD or the Win2K Server Resource Kit.To use Netdom to view the FSMO role holders, open a command prompt window and type:netdom query fsmo and press enter. You will see a list of the FSMO role servers:

5. Active Directory Relication Monitor another tool that comes with the Support Tools is the Active Directory Relication Monitor. Open this utility from Start, Programs, Windows 2000 Support Tools. Once open, click Edit, Add Monitored Server and add the name of a Domain Controller. Once added, right click the Server name and choose properties. Click the FSMO Roles tab to view the servers holding the 5 FSMO roles (below). You cannot change roles using Replication Monitor, but this tool has many other useful purposes in regard to Active Directory information. It is something you should check out if you haven't already. Finally, you can use the Ntdsutil.exe utility to gather information about and change servers for FSMO roles. Ntdsutil.exe, a command line utility that is installed with Windows 2000 server, is rather complicated and beyond the scope of this document.
6. DUMPFSMOS
Command-line tool to query for the current FSMO role holders
Part of the Microsoft Windows 2000 Server Resource Kit
Downloadable from http://www.microsoft.com/windows2000
/techinfo/reskit/default.asp
Prints to the screen, the current FSMO holders
Calls NTDSUTIL to get this information
7. NLTEST
Command-line tool to perform common network administrative tasks
Type “nltest /?” for syntax and switches
Common uses
Get a list of all DCs in the domain
Get the name of the PDC emulator
Query or reset the secure channel for a server
Call DsGetDCName to query for an available domain controller

8. Adcheck (470k) (3rd party)
A simple utility to view information about AD and FSMO roles
http://www.svrops.com/svrops/downloads/zipfiles/ADcheck.msi

Q9. How to Transfer and Seize a FSMO Role
http://support.microsoft.com/default.aspx?scid=kb;en-us;Q255504

GROUP POLICY

Q1. What are Group Policies?

Group Policies are settings that can be applied to Windows computers, users or both. In Windows 2000 there are hundreds of Group Policy settings. Group Policies are usually used to lock down some aspect of a PC. Whether you don't want users to run Windows Update or change their Display Settings, or you want to insure certain applications are installed on computers - all this can be done with Group Policies.

Group Policies can be configured either Locally or by Domain Polices. Local policies can be accessed by clicking Start, Run and typing gpedit.msc. They can also be accessed by opening the Microsoft Management Console (Start, Run type mmc), and adding the Group Policy snap-in. You must be an Administrator to configure/modify Group Policies. Windows 2000 Group Policies can only be used on Windows 2000 computers or Windows XP computers. They cannot be used on Win9x or WinNT computers.

Q2. Domain policy gets applied to whom ?

Domain Policies are applied to computers and users who are members of a Domain, and these policies are configured on Domain Controllers. You can access Domain Group Polices by opening Active Directory Sites and Services (these policies apply to the Site level only) or Active Directory Users and Computers (these policies apply to the Domain and/or Organizational Units).
Q3. From Where to create a Group Policy?To create a Domain Group Policy Object open Active Directory Sites and Services and right click Default-First-Site-Name or another Site name, choose properties, then the Group Policy tab, then click the New button. Give the the GPO a name, then click the Edit button to configure the policies.For Active Directory Users and Computers, it the same process except you right click the Domain or an OU and choose properties.

Q4. Who can Create/Modify Group Policies?
You have to have Administrative privileges to create/modify group policies. The following table shows who can create/modify group policies:
Policy Type
Allowable Groups/Users
Site Level Group Policies
Enterprise Administrators and/or Domain Administrators in the root domain. The root domain is the first domain created in a tree or forest. The Enterprise Administrators group is found only in the root domain.
Domain Level Group Policies
Enterprise Administrators, Domain Administrators or members of the built-in group - Group Policy Creator Owners. By default only the Administrator user account is a member of this group
OU Level Group Policies
Enterprise Administrators, Domain Administrators or members of the Group Policy Creator Owners. By default only the Administrator user account is a member of this group.Additionally, at the OU level, users can be delegated control for the OU Group Policies by starting the Delegate Control Wizard (right click the OU and choose Delegate Control). However, the wizard only allows the delegated user to Link already created group policies to the OU. If you want to give the OU administrators control over creating/modifying group policies, add them to the Group Policy Creator Owners group for the domain.
Local Group Policies
The local Administrator user account or members of the local Administrators group.

Q5. How are Group Policies Applied?
Group Polices can be configured locally, at the Site level, the Domain level or at the Organizational Unit (OU) level. Group Policies are applied in a Specific Order, LSDO - Local policies first, then Site based policies, then Domain level policies, then OU polices, then nested OU polices (OUs within OUs). Group polices cannot be linked to a specific user or group, only container objects.In order to apply Group Polices to specific users or computers, you add users (or groups) and computers to container objects. Anything in the container object will then get the policies linked to that container. Sites, Domains and OUs are considered container objects.Computer and User Active Directory objects do not have to put in the same container object. For example, Sally the user is an object in Active Directory. Sally's Windows 2000 Pro PC is also an object in Active Directory. Sally the user object can be in one OU, while her computer object can be another OU. It all depends on how you organize your Active Directory structure and what Group Policies you want applied to what objects.

User and Computer PoliciesThere are two nodes in each Group Policy Object that is created. A Computer node and a User Node. They are called Computer Configuration and User Configuration (see image above). The polices configured in the Computer node apply to the computer as a whole. Whoever logs onto that computer will see those policies.Note: Computer policies are also referred to as machine policies.User policies are user specific. They only apply to the user that is logged on. When creating Domain Group Polices you can disable either the Computer node or User node of the Group Policy Object you are creating. By disabling a node that no policies are defined for, you are decreasing the time it takes to apply the polices.To disable the node polices: After creating a Group Policy Object, click that Group Policy Object on the Group Policy tab, then click the Properties button. You will see two check boxes at the bottom of the General tab.It's important to understand that when Group Policies are being applied, all the policies for a node are evaluated first, and then applied. They are not applied one after the other. For example, say Sally the user is a member of the Development OU, and the Security OU. When Sally logs onto her PC the policies set in the User node of the both the Development OU and the Security OU Group Policy Objects are evaluated, as a whole, and then applied to Sally the user. They are not applied Development OU first, and then Security OU (or visa- versa).The same goes for Computer policies. When a computer boots up, all the Computer node polices for that computer are evaluated, then applied. When computers boot up, the Computer policies are applied. When users login, the User policies are applied. When user and computer group policies overlap, the computer policy wins.Note: IPSec and EFS policies are not additive. The last policy applied is the policy the user/computer will have.When applying multiple Group Policies Objects from any container, Group Policies are applied from bottom to top in the Group Policy Object list. The top Group Policy in the list is the last to be applied. In the above image you can see three Group Policy Objects associated with the Human Resources OU. These polices would be applied No Windows Update first, then No Display Settings, then No ScreenSaver. If there were any conflicts in the policy settings, the one above it would take precedence.

Q6.How to disable Group Policy ObjectsWhen you are creating a Group Policy Object, the changes happen immediately. There is no "saving" of GPOs. To prevent a partial GPO from being applied, disable the GPO while you are configuring it. To do this, click the Group Policy Object on the Group Policy tab and under the Disable column, double click - a little check will appear. Click the Edit button, make your changes, then double click under the Disable column to re-enable the GPO. Also, if you want to temporarily disable a GPO for troubleshooting reasons, this is the place to do it. You can also click the Options button on the Group Policy tab and select the Disabled check box.

Q7. When does the group policy Scripts run?Startup scripts are processed at computer bootup and before the user logs in.Shutdown scripts are processed after a user logs off, but before the computer shuts down.Login scripts are processed when the user logs in.Logoff scripts are processed when the user logs off, but before the shutdown script runs.

Q8. When the group policy gets refreshed/applied?Group Policies can be applied when a computer boots up, and/or when a user logs in. However, policies are also refreshed automatically according to a predefined schedule. This is called Background Refresh.
Background refresh for non DCs (PCs and Member Servers) is every 90 mins., with a +/- 30 min.interval. So the refresh could be 60, 90 or 120 mins. For DCs (Domain Controllers), background refresh is every 5 mins.Also, every 16 hours every PC will request all group policies to be reapplied (user and machine) These settings can be changed under Computer and User Nodes, Administrative Templates,System, Group Policy.
Q9. Which are the policies which does not get affected by background refresh?
Policies not affected by background refresh. These policies are only applied at logon time: Folder RedirectionSoftware InstallationLogon, Logoff, Startup, Shutdown Scripts
Q9. How to refresh Group Policies suing the command line?Secedit.exe is a command line tool that can be used to refresh group policies on a Windows 2000 computer. To use secedit, open a command prompt and type:secedit /refreshpolicy user_policy to refresh the user policiessecedit /refreshpolicy machine_policy to refresh the machine (or computer) policies
These parameters will only refresh any user or computer policies that have changed since the last refresh. To force a reload of all group policies regardless of the last change, use:secedit /refreshpolicy user_policy /enforcesecedit /refreshpolicy machine_policy /enforceGpupdate.exe is a command line tool that can be used to refresh group policies on a Windows XP computer. It has replaced the secedit command. To use gpupdate, open a command prompt andtype:gpupdate /target:user to refresh the user policiesgpupdate /target:machine to refresh the machine (or computer) policies
As with secedit, these parameters will only refresh any user or computer policies that have changed since the last refresh. To force a reload of all group policies regardless of the last change, use:gpupdate /forceNotice the /force switch applies to both user and computer policies. There is no separation of the two like there is with secedit
Q10. What is the Default Setting for Dial-up users?
Win2000 considers a slow dial-up link as anything less than 500kbps. When a user logs into a domain on a link under 500k some policies are not applied.
Windows 2000 will automatically detect the speed of the dial-up connection and make a decision about applying Group Policies.
Q11. Which are the policies which get applied regardless of the speed of the dial-up connection?
Some policies are always applied regardless of the speed of the dial-up connection. These are:
Administrative TemplatesSecurity SettingsEFS RecoveryIPSec

Q12. Which are the policies which do not get applied over slow links?
IE Maintenance SettingsFolder RedirectionScriptsDisk Quota settingsSoftware Installation and Maintenance
These settings can be changed under Computer and User Nodes, Administrative Templates,System, Group Policy.
If the user connects to the domain using "Logon Using Dial-up Connection" from the logon screen, once the user is authenticated, the computer policies are applied first, followed by the user policies.
If the user connects to the domain using "Network and Dial-up Connections", after they logon, the policies are applied using the standard refresh cycle.
Q13. Which are the two types of default policies?
There are two default group policy objects that are created when a domain is created. The Default Domain policy and the Default Domain Controllers policy.Default Domain Policy - this GPO can be found under the group policy tab for that domain. It is the first policy listed. The default domain policy is unique in that certain policies can only be applied at the domain level.If you double click this GPO and drill down to Computer Configuration, Windows Settings, Security Settings, Account Policies, you will see three policies listed:Password PolicyAcount Lockout PolicyKerberos PolicyThese 3 policies can only be set at the domain level. If you set these policies anywhere else- Site or OU, they are ignored. However, setting these 3 policies at the OU level will have the effect of setting these policies for users who log on locally to their PCs. Login to the domain you get the domain policy, login locally you get the OU policy.If you drill down to Computer Configuration, Windows Settings, Security Settings, Local Policies, Security Options, there are 3 policies that are affected by Default Domain Policy:Automatically log off users when logon time expiresRename Adminsitrator Account - When set at the domain level, it affects the Domain Administrator account only.Rename Guest Account - When set at the domain level, it affects the Domain Guest account only.The Default Domain Policy should be used only for the policies listed above. If you want to create additional domain level policies, you should create additional domain level GPOs.Do not delete the Default Domain Policy. You can disable it, but it is not recommended.Default Domain Controllers Policy - This policy can be found by right clicking the Domain Controllers OU, choosing Properties, then the Group Policy tab. This policy affects all Domain Controllers in the domain regardless of where you put the domain controllers. That is, no matter where you put your domain controllers in Active Directory (whatever OU you put them in), they will still process this policy.Use the Default Domain Controllers Policy to set local policies for your domain controllers, e.g. Audit Policies, Event Log settings, who can logon locally and so on.

Q14.How to restore Group policy setting back to default?
The following command would replace both the Default Domain Security Policy and Default
Domain Controller Security Policy. You can specify Domain or DC instead of Both, to only
restore one or the other.

> dcgpofix /target:Both

Note that this must be run from a domain controller in the target domain where you want to reset the GPO

If you've ever made changes to the default GPOs and would like to revert back to the original
settings, the dcgpofix utility is your solution. dcgpofix works with a particular version of
schema. If the version it expects to be current is different from what is in Active Directory, it
not restore the GPOs. You can work around this by using the /ignoreschema switch, which
restore the GPO according to the version dcgpofix thinks is current. The only time you might
experience this issue is if you install a service pack on a domain controller (dc1) that extends
schema, but have not installed it yet on a second domain controller (dc2). If you try to run

dcgpofix from dc2, you will receive the error since a new version of the schema and the
dcgpofix utility was installed on dc1.

Resolving GPOs from Multiple Sources

Because GPOs can come from different sources to apply to a single user or computer, there must be a way of determining how those GPOs are combined. GPOs are processed in the following order:

1. Local GPO The local GPO on the computer is processed and all settings specified in that GPO are applied.

2. Site GPOs GPOs linked to the site in which the computer resides are processed. Settings made at this level override any conflicting settings made at the preceding level. If multiple GPOs are linked to a site, the site administrator can control the order in which those GPOs are processed.

3. Domain GPOs GPOs linked to the domain in which the computer resides are processed and any settings are applied. Settings made at the domain level override conflicting settings applied at the local or site level. Again, the administrator can control the processing order when multiple GPOs are linked to the domain.
4. OU GPOs GPOs linked to any OUs that contain the user or computer object are processed. Settings made at the OU level override conflicting settings applied at the domain, local, or site level. It is possible for a single object to be in multiple OUs. In this case, GPOs linked to the highest level OU in the Active Directory hierarchy are processed first, followed by the next highest level OU, and so on. If multiple GPOs are linked to a single

Q15. What are the two exceptions to control the inheritance of the group policy?

■ No Override When you link a GPO to a container, you can configure a No Override option that prevents settings in the GPO from being overridden by settings in GPOs linked to child containers. This provides a way to force child containers to conform to a particular policy.
■ Block Inheritance You can configure the Block Inheritance option on a container to prevent the container from inheriting GPO settings from its parent containers. However, if a parent container has the No Override option set, the child container cannot block inheritance from this parent.

Q16. How to Redirect New User and Computer Accounts?

By default, new user and computer accounts are created in the Users and Computers containers, respectively. You cannot link a GPO to either of these built-in containers. Even though the built-in containers inherit GPOs linked to the domain, you may have a situation that requires user accounts and computer accounts to be stored in an OU to which you can link a GPO. Windows Server 2003 includes two new tools that let you redirect the target location
for new user and computer accounts. You can use redirusr.exe to redirect user accounts and redircomp.exe to redirect computer accounts. Once you choose the OU for redirection, new user and computer accounts are created
directly in the new target OU, where the appropriate GPOs are linked. For example, you could create an OU named New Users, link an appropriate GPO to the OU, and then redirect the creation of new-users accounts to the New Users OU. Any new users created would immediately be affected by the settings in the GPO. Administrators could then move the new user accounts to a more appropriate location later. You can find both of these tools in the %windir%\system32 folder on any computer running Windows Server 2003. You can learn more about using these tools in Knowledge Base article 324949, “Redirecting the Users and Computers Containers in Windows Server 2003 Domains,” in the Microsoft Knowledge Base at http://support.microsoft.com.

Q17. What permissions should a administrator have to manage GPOs?

Editing GPOs linked to sites requires Enterprise Administrative permissions.
Editing GPOs linked to domains requires Domain Administrative
Editing GPOs linked to OUs requires permissions for the OU.

Q18. What is the client requirement for supporting GPOs?

For client computers to accept Group Policy settings, they must be members of Active Directory. Support for Group Policy for key operating systems includes the following:

■ Windows 95/98/Me do not support Group Policy.
■ Windows NT 4.0 and earlier versions do not support Group Policy.
■ Windows 2000 Professional and Server support many of the Group Policy settings available in Windows Server 2003, but not all. Unsupported settings are ignored.
■ Windows XP Professional, Windows XP 64-bit Edition, and Windows Server 2003 fully support Group Policy.

ACTIVE DIRECTORY – DNS – FSMO – GROUP POLICY

2008-03-07T18:35:00.000-08:00