StorageTrendz

Failover at multiple level in storage networks

2008-12-13T14:29:00.005+05:30

Storage networks can be broadly classified into 3 levels and the fail over or Redundancy feature is very important aspect of IT storage business and it is implemented in every interconnecting components in the networks.
Host or Server(s) Level
Network Level
Storage sub-system(s) Level

Fail-Over:
If the data passage path of any of the component in the storage networks fails, the auto-mechanism that provides an alternate path instantly to avoid the data loss is called fail-over.
Example: If a component such as a RAID controller module or a cable fails, or an error occurs on the data path to the preferred RAID controller module, virtual disk ownership is moved to the alternate non preferred RAID controller module for processing. This failure or error is called failover.

Host or Server Level:
Hosts or servers are associated with few interconnect peripherals such as Host Bus Adapter [HBA], Ethernet adapters et al. some common fail-over feature implementations that you see is at the HBA device in the form of Fail-over driver such as MPP or MPIO [Multi Path driver].
Another stage of fail-over implementation could be to the entire host or server in the form of Clustering, Microsoft Clustering or Linux or Solaris or Unix clustering.

Network Level:
At Switches or Routers, we can provide fail-over by connecting one port or path of the servers & storage sub-systems to one switch port & another port or path connected through another switch port. thus we need at the least two switches to handle the Preferred path & Alternative path of data passage.
usually such setups are know as High Availability Fail-over setup.

Sub-system Level:
Within the SAN storage sub-systems, there are multiple components such as RAID Processors or controllers, Hard disks, Drive trays, power supplies et al.
At Hard disk level , RAID & Hot sparing is used in co-operation with RAID processors as fail-over.
At Drive tray or Enclosure level, there will be dual Service Modules that act as fail-over.
At the RAID Processor or Controller level, there will be Dual RAID processors or Controllers that provide fail-over mechanism.

Fail-over is very vast concept and there are plenty of ways to implement it at different components of the storage networks. for more information you can always buzz me on Email.

Terrorism is a dangerous mental disorder or disease

2008-11-28T22:29:00.004+05:30

******The views expressed in this blog is my personal feelings **********

First thing first - Terrorism any where in any part of our beautiful world is unacceptable & i strongly condemn it.
Today, am tempted to write this blog as i felt the top priority problem the whole world facing is Terrorism.
in my personal view & with all respect to my understanding about global living style. i declare its time to say we are one globe (not individual countries).
i declare probably the first person to say "Terrorism is a global disease (like AIDS or something else), it is a mental disorder and we have the at most global challenge to eradicate it.
it is not easy to eradicate as it is mental disorder. we the global human beings should unite & create a global anti-terrorism framework.
this problem can not be solved by just having anti-terror squad or Intelligence bureau or defense force. this is the time to understand about the nature of disease and find out a near to perfect vaccine.
i think the best vaccine for this is going to be years of mental caring for each and every individual of the globe.

Solutions:

* Change the entire education system starting from the baby-sitting till the end of life of the individual.
* Education system is the best mechanism to deal with this problem. all over globe include terror & terrorism as mandatory subject of studies & then focus to establish a terrorism syllabus that can be related by each & every individual and interesting enough to learn.
important point to keep in mind is the syllabus should bring out the negativity of the terrorism & show the positive way of dealing with it.
* The need of the hour is not just being defensive about terrorism but to make sure that every individual on earth will have in his blood to fight against terrorism & also, never choose the terrorism as profession.
* Mental disorder like "Terrorism" is very dangerous & it is slowly contaminating the blood of every individual of the globe. so act fast before it engulf us.
* Along with education, we should have a global Anti-terror framework & Global intelligence bureau or Global defense force because to eradicate the mental disorder "terrorism", we should be prepared with multi-level solutions.
* Make it mandatory that every personal of this globe should compulsorily work in armed force for at least 2 years or social service for at least 3 years before taking up their individual profession or Business.
* every country on the earth should be uniformly follow all these frame work and if any country not doing it, will be punished in all means by the rest of the world.
* Idea is to make sure we have every individual on earth who has the best education for Anti-terrorism, practical exposure to actual life in terms of Armed force or Social service Job.
* Idea is to create a global sense that "we the human beings, are the only one of our kind & we the one globe on the Earth".

IP based SAN Technologies:

2008-09-22T20:33:00.004+05:30

On request by few of my blog readers, i will be posting iSCSI specific information in my upcoming posts.

Storage Neworking technologies from past few decades was dominated by the high speed serial Fibre channel [FC] & SCSI [Small Computer System Interface], the implementation use to be for limited enterprises because of high cost of implementation.
over the period of time, Technology evolved & more enterprise inter-network demands resulted in rapid innovations for implementing the storage networks to work on traditional & highly conventional TCP/IP protocol technology.
As a initial innovation result FCIP & iFCP were implemented. the TCP/IP protocol is used as Gateway protocol on Gateway devices that inter connect the two or more FC SAN sub-networks.

FCIP: Fibre Channel over TCP/IP
* A TCP/IP based tunneling protocol for connecting geographically distributed Fibre Channel SANs transparently to both FC and IP.
* Provides a mechanism to tunnel Fibre Channel over IP based networks
* Leverage IP infrastructure to interconnect and extend FC SAN.
* FCIP Gateways enable to connect to a standard Gigabit Ethernet/IP network.
* Cost effective
* The FCIP gateway can be a separate device, or its functionality can be integrated into the Fibre Channel switch.
* Can be deployed over LANs, MANs and WANs

iFCP: Internet Fibre Channel Protocol
* iFCP is TCP/IP based Session protocol for connecting two or more FC SANs, two devices from two different FC SANs.
* Fibre Channel devices (e.g., switches, disk arrays, and HBAs) connect to an iFCP gateway or switch. Each Fibre Channel session is terminated at the local gateway and converted to a TCP/IP session via iFCP.
A second gateway or switch receives the iFCP session and initiates a Fibre Channel session.
* Sessions include device-to-device, device-to-SAN, and SAN-to-SAN communications.

Pictures attached with this post will give you brief idea about FCIP, iFCP & iSCSI.

The latest & hottest TCP/IP implementation is iSCSI protocol & the entire SAN can be designed on Ethernet or TCP/IP technology using iSCSI Protocol structure.
i will be posting detailed information about iSCSI technology in the upcoming posts, watch out this space.....

More about VMware Virtual Datacenter OS

2008-09-18T22:37:00.007+05:30

Summary of the keynote given at VMWorld VMware conference sep 2008:

* Virtual Infrastructure 4.0 itself has not been announced, yet the major components have already been introduced:

* Virtual Datacenter OS [VDC OS] consists of the following:

o the hardware/interaction layer:
vCompute - platform that interacts with the hardware, with vCompute the hardware specifications have been adapted to:
# 8 virtual CPUS
# 256GB per VM
# 40 GB/s network throughput
# up to 64 nodes per cluster
# up to 4906 cores to manage
# full support for DPM
* vStorage - new features have also been announced on the level of storage. VMFS and storage vMotion will be extended with stroage thin provisioning and linked clones
* vNetwork - the network layer functionalities have been improved with virtual distributed networking and support for 3rd party solutions.

o the application layer:
# vAPP: gives applications priorities and SLA levels (hello legal disagreement with Microsoft?)
# VMware FT: high availability with 2 vMs in sync (like Marathon Technologies everrun VM)
# Security (shouldn’t that be vSecurity?): VMsafe APIs on the way

o The management layer
# Virtual Center - vCenter with chargeback, performance optimization, orchestration and many other modules
# vCenter server component will be available for Linux (as virtual appliance)

We have not yet received any confirmation on the general availability of VI4 (of which VDC-OS will be a big part), yet the solution seems to be in beta or beta 2.

Software Technology VS Hardware Technology

2008-09-18T22:37:00.006+05:30

In the Enterprise environment Hardware design & implementation was happening at never before pace. each hardware vendors (IBM, HP, Intel, AMD, SUN, Dell, EMC2, NetApp & 1000's of many more small & big enterprises) tried to come up with highly competitive technologies & they did succeeded in their achievements to a larger extent.
The Hardware innovations continue to evolve as it is happening from past few decades with even higher pace. the advancement in the multiple-core processor technologies being implemented by Intel & other vendors will continue to boast other hardware (servers, Switches, routers, storage appliances etc.) innovations in future.
But another interesting point i like to make here is about "Enterprise Software Technology". in the recent decade, Enterprise Software does not mean just Operating System (OS), it is more than just OS, we have seen enterprise Management software, Network management software, Telecom network management software, Wireless management software to name a few.
very recently, VMWARE's virtualization software success has taken the Enterprise industries by surprise & it has resulted in "Software Enterprise Technology" showdown by some of the biggest software players such as Microsoft, Xensource,SUN, IBM, HP etc. this is interesting as the enterprise software fever is catching up like wild fire, more & more competitors are born every day.
Software being easy and cost effective Technology to design & implement, there is going to be Enterprise software Revolution in the cards. one of the first sign was Virtualization software of VMware & now Microsoft windows 2008 OS.
very recently, in the just concluded VMware's VMWorld conference in Las vegas, USA. VMware announced that it is building nothing less than a "virtual datacenter OS" -- VDC OS for short -- that will eventually make traditional operating systems "all but disappear."
This is the next sign of Enterprise Software Revolution that i am talking about.

If you like to know more details of it, check out http://weblog.infoworld.com/fatalexception/archives/2008/09/vmware_proposes.html

Latest Storage market status - Q2 2008

2008-09-13T23:27:00.003+05:30

HP, IBM, Dell, SUN are all top global enterprises with broad range of products, here i have current market status for these companies in External Storage segment only.

According to analyst group IDC, Despite tough conditions in the U.S. economy, which have decreased demand for everything from new homes to semiconductors, the market for computer data storage Relevant
Products/Services systems is going strong.
EMC continued to lead the external disk storage systems market with 21.7 percent of the revenue share, followed by IBM at 13.1 percent, HP at 12.9 percent, Dell at 9.2 percent, NetApp at 8.0 percent and Hitachi at 7.6 percent. Of the top five suppliers, EMC and NetApp posted the strongest year-over-year revenue growth at 19.7 percent and 17.2 percent, respectively.
The Open SAN market grew 15.5 percent year-over-year, with EMC leading with 23.9 percent of revenue share, followed by HP at 16.7 percent. The NAS market experienced year-over-year growth of 23.5 percent, with EMC leading with 39.8 percent of revenue share, followed by NetApp at 28.5 percent. The iSCSI SAN market showed year-over-year revenue growth of 93.9 percent, with Dell leading the market (due to its acquisition of EqualLogic) with 32.8 percent of the revenue share, followed by NetApp at 14.6 percent and EMC at 14.1 percent.

**********for more information check out http://www.echannelline.com/usa/story.cfm?item=23687 *******************

IBM's Storage product Buzz:

2008-09-13T12:56:00.003+05:30

In Sep 2008, IBM announces 30 new products and services, saying that it took an investment of $2 billion, three years, and 2,500 engineers and other specialists from nine countries to complete the project.
IBM said that all the new products and services fall under the auspices of its New Enterprise Data Center strategy, which utilizes intellectual property IBM has acquired in the last two years.

Few of them are listed below & you can get more info from http://www-03.ibm.com/systems/storage/product/showcase/index.html
Newly-announced storage products
IBM XIV Storage System
IBM TS7650G ProtecTIER De-duplication Gateway
IBM System Storage TS2900 Tape Autoloader
IBM System Storage DS5000 series
IBM System Storage DS8000 R4.0/4.1
IBM System Storage TS3500 high-density frames
IBM N Series N6000
IBM N Series SnapManager for Virtual Infrastructure
IBM N Series OSSV SnapVault

Latest information about IBM's DS5000 product here http://storagetrendz.blogspot.com/2008/09/ibm-new-ds5000-storage-product-released.html

IBM New DS5000 Storage Product released:

2008-09-12T22:40:00.002+05:30

Disclaimer: The opinions expressed by the Blogger and those providing comments are theirs alone, and we are not responsible for the accuracy of any of the information supplied by the Bloggers.

Most of the Netizens beleive IBM DS5000 storage product came from the acquisition of XIV storage company by IBM [check http://www.xivstorage.com/].
but i differ with this wide perception. the DS5000 which is released by IBM in sep, 2008 looks to me as an extension of IBM's old products in the mid-range (ex:DS4000 series).
yet again i like to differ myself saying it is not extension, it is whole new enterprise storage architecture and silent features are given below:
* offers improved performance.
* Scalability of FC/SATA disks upto 448.
* Boost up with 8G FC & 10G iSCSI connectivity.
* PCI-Express (PCI-e) bus architecture & so on.
* Supports RAID levels RAID 0, 1, 3, 5, 6 and 10 (RAID 1+0).
* Supports up to 2048 volumes & 2048 host logins.
* Premium features FlashCopy (up to 16 copies per volume), VolumeCopy, Remote Volume Mirroring (up to 128 pairs).
* Cache memory of 8GB to 16GB cache & USB Cache backup memory for Power failures.
* IBM DS5000 series offers two models
DS5100
DS5300
Obviously for EMC & HP bloggers, DS5000 series looks no threat to their Clariion & EVA products respectively but there are specific indications
that DS5000 series future offerings will be definitely going to cut the EMC & HP business in this segment (Keep watch on this).
the beauty of this product is that it has the potential to bridge the gap between IBM's Mid-range & high range (DS8000) product offerings.

The pictures associated with this post gives you more performance & scalability offering of DS5000

IBM Storage Products

2008-09-06T21:03:00.004+05:30

NOTE: IBM has comprehensive range of storage hardware & software products such as servers, SAN, NAS, Switch, Tape libraries, switches & SAN arrays, NAS devices etc. so here am listing only few storage specific products.

IBM Disk storage subsystems
Enterprise systems - DS6000 and DS8000 family
DS6000 series
DS8000 series
DCS9550

Mid-range systems - DS4000 family
DS5000
DS4800
DS4700 Express
DS4200

Entry level systems - DS3000 family
DS3200
DS3300
DS3400

Enterprise SAN directors [High end switches]
For highest availability and scalability enterprise solutions.
IBM System Storage SAN768B
IBM TotalStorage SAN256B
IBM TotalStorage SAN140M
IBM TotalStorage SAN256M

Mid-range SAN switches
For scalable, affordable SMB and enterprise solutions.
IBM System Storage SAN80B-4
IBM System Storage SAN64B-2
IBM System Storage SAN40B-4
IBM System Storage SAN32B-3

Entry SAN switches
For simple, affordable small and medium business (SMB) solutions.
IBM System Storage SAN24B-4 Express
IBM TotalStorage SAN16B-2

IBM Express Model SAN switches
For affordable, simple-to-use small and medium business (SMB) solutions.
IBM System Storage SAN24B-4
IBM TotalStorage SAN16B-2

Tivoli Storage Manager
Manage risk through complete storage management with enhanced performance and access for Sequential Disk. Manage complexity with encryption key management. used by more than 21,000 customers.

OEM Storage Management softwares
Basically OEM storage product software marketed with IBM logo.

IBM TotalStorage Productivity Center
Identify, evaluate, control and predict the growth of data through its lifecycle to meet storage service levels.

IBM System Storage Virtualization
Designed to help simplify storage infrastructure, optimize storage utilization, and enable business to adapt quickly and dynamically to variable environments

HP Storage Products

2008-09-05T21:21:00.001+05:30

NOTE: HP has comprehensive range of stroage hardware & software products such as servers, SAN, NAS, Switch & HBA software, HBA's, switches & SAN arrays, NAS devices etc. so here am listing only few storage specific products.

Disk Storage Systems [SAN]

XP Disk Array - High Level
[HP StorageWorks XP24000 Disk Array, XP20000 Disk Array, XP12000 Disk Array, XP10000 Disk Array]
• Bulletproof storage for 24x7 business continuity demands
• Massive consolidation for greater efficiency
• Virtualization platform for internal and external data

EVA Disk Arrays - Mid-level
[HP StorageWorks Enterprise Virtual Array 8100, EVA6100, EVA4400, EVA4100 & EVA Software]
• Powerfully simple enterprise class storage
• Affordable and virtualized storage with a low entry price and low total cost of ownership
• Reliable and available

MSA Disk Arrays - Entry level
[HP StorageWorks Modular Smart Array 2000sas, MSA2000fc, MSA2000i & Storage Resource Management Software (SRM)]
• Flexibility to start small and migrate drives & enclosures into larger configurations
• Increase server capacity
• Modular design enables expansion

NAS Systems
[HP All-in-One AiO1200r SATA, AiO1200r SAS, AiO600, AiO400t, AiO400r,AiOSB600c]
• Unbelievably simple: No storage expertise required
• Uniquely affordable: A complete storage solution
• Unquestioningly reliable: Integrated data protection and HP reliability

Scalable NAS

• Scalable, Available Enterprise NAS
• Windows and Linux File Serving
• Oracle over NFS, Microsoft SQL Server Consolidation

Switches
B-series [Fabric switches, Blade switches, Director switches]
• B-series switches and directors are used by small departments and global organizations to access and share data in a consolidated, manageable, and a scalable manner.
C-Series [Fabric switches, Blade switches, Director switches]
• C-series family of multilayer directors and fabric switches is a comprehensive line of SAN switches that provides an effective way to access, manage, and protect growing information resources.
• C-series switches are basically CISCO switches marketed by HP.

HP Storage Software

• Storage Resource Management Software (SRM)

• HP StorageWorks EVA Device Management Software
• HP StorageWorks EVA Replication Software

• HP StorageWorks XP Replication Software
• HP StorageWorks XP Device Management Software

• HP Storage Data Protection and Recovery Software
• HP StorageWorks Storage Replication Software
• NAS Device Management Software
• B-series Switch Device Management Software
• C-series Switch Device Management Software

StorageTrendz: Host Bus Adapter [HBA]

2008-08-31T00:56:00.001+05:30

StorageTrendz: Host Bus Adapter [HBA]

StorageTrendz: LUN Mapping, Persistent Binding, LUN Masking & Fabric Zoning

2008-08-31T00:52:00.001+05:30

StorageTrendz: LUN Mapping, Persistent Binding, LUN Masking & Fabric Zoning

StorageTrendz: EMC Storage Products lineage part1:

2008-08-31T00:50:00.000+05:30

StorageTrendz: EMC Storage Products lineage part1:

Web based Storage & Virtualization Training

2008-08-20T21:10:00.003+05:30

NOTE: this blog post is borrowed from other sites. just for the sake of readers request " FAQ: any training centers available in storage in Bangalore?".
Learning through Videos is the fastest & most effective method after learning from an instructor or a personal trainer. Cost of a personal trainer is high to learn Storage technology hence a team I know very well is developing a website for Storage fundamentals + SAN training using Videos. Learning from Videos that too Web based videos has advantages like
- you learn at your own pace,
- you replay the video & see it number of times to perfect the concept or technology

A separate website is being developed by a team of Storage professionals who will be Sharing some of their industry experiences,
Giving you tips for a Career in Storage technology
But main focus will be to give you a Strong Fundamental knowledge on Storage technology

The topics covered will be around(This is just the initial list I got they promised that it will grow more soon, lot more will be covered)
Storage Basics
SAN(Storage Area Network): SAN components
SAN Hardware
SAN Software
SAN Configuration & Troubleshooting overview
iSCSI (SCSI over IP)
FC (Fibre Channel)
Storage connectivity & interfaces:SCSI,SAS,SATA & more.

There will be huge bonus additional Videos & materials like
- What to expect in Storage job interviews
- Tips to prepare your resume to get more interviews from Storage companies
- Tips for interview preparation for Storage technology job openings
- Tips for prioritizing what to give importance & which topics you need to perfect
- You will receive 300+ interview questions from different Storage company interviews which itself is valued at $100. You get this free when you join for this Video training membership website.

Cost for this web based training access will be $500 (USD) payable through paypal or credit card. Those who are interested please email semiconsys@gmail.com today & confirm your interest. The access to this membership based website will be limited only to few since the website development team wants to work more closely with the members & provide some additional value adds, hence I would recommend you to email today & confirm your interest to join.

You will soon get to see a preview Video from their list of Storage Technology Videos on this blog. You will also see lot more updates about this new website being developed soon on this blog.May be I will post some of the reviews or Videos from members who joined & benefited from this web based training website.

EMC Storage Products lineage part1:

2008-08-11T22:32:00.000+05:30

Hardware

Celerra - NAS family
NAS product line of EMC. the products include NAS gateways, NAS storage devices & integrated devices.
CLARiiON - SAN family
Clariion series is the SAN products for entry-midrange-entrylarge level models to tap the high selling market segment.
Prodocuts includes FC & iSCSI san architectures.
Connectrix - Switches or Fabrics family
Move your organization's vital information where it needs to go—quickly, easily, and reliably. Advanced directors and switches make it happen. Get best-in-class availability and easy management.
Centera - CAS family
Store and manage your "fixed content"—unchanging digital assets—and keep them available online and accessible. All with EMC Centera® content-addressed storage (CAS) systems. Be ready for growth with petabyte scalability.
Symmetrix - SAN infrasture family
Make high-end networked storage part of your information infrastructure with systems that take performance, availability, and security to new heights. Manage and protect your information today—and expand in the future.

Software

ControlCenter[Multi-vendor management software]
Simplify and automate key tasks—such as discovery, monitoring, reporting, planning, and provisioning—for even the largest, most complex storage environments.
Celerra Manager[NAS management Spftware]
Easily configure, administer, and monitor your EMC Celerra IP storage environment from a single web-based interface—ensuring high availability.
Navisphere Management Suite [SAN management software]
Get simple, secure, web-based management from any location. Discover, monitor, configure, and report on multiple CLARiiON arrays from your browser. Use these insights to get more value from your investment.
PowerPath
Enable EMC host-based solutions including multipathing, data migration, and host-based encryption.
Symmetrix Dynamic Cache Partitioning
Enable the consolidation of multiple workloads in a single Symmetrix while maintaining predictable performance.
Symmetrix Management Console [Symmetrix management software]
Simplify day-to-day management of your EMC Symmetrix storage with this powerful, easy-to-use browser-based management tool.
Symmetrix Virtual Provisioning
Increase storage capacity utilization, improve ease of use, and enhance performance for certain applications and workloads.

LUN Mapping, Persistent Binding, LUN Masking & Fabric Zoning

2008-06-04T12:03:00.001+05:30

***** For Expert Consultation contact me storagetrendz@gmail.com *********

LUN Mapping:
LUN Mapping is host-centric method of storage LUN visibility management. LUN Mapping selectively allows a system administrator to scan for specified SCSI targets and LUNs at storage-driver boot time and to ignore selectively non-specified SCSI targets and LUNs.
The advantage of LUN Mapping is that it provides a level of security management in SANs where LUN Masking is not an option, perhaps because it is not supported
on the storage hardware.
The disadvantage is that LUN Mapping is configured and enabled on a host-by-host basis. It requires good coordination among the administrators of the systems sharing the storage, which ensures that only one host sees certain storage unless planned, as in a clustered server configuration.

Persistent Binding:
It is another host-centric method. This can be implemented in Operating systems (OS) by assigning specific SCSI-Target IDs to the Storage LUNs.

LUN Masking:
LUN Masking is RAID storage subsystem-centric method of LUN visibility management to hosts or servers.
LUN Masking makes sure that each RAID controller is configured to allow each host to see only a subset of the actual LUN's & hide all other LUNs from it. so all connected hosts will see only those LUNs that are assigned to them.
The advantage of LUN Masking is easy to implement in storage subsystems and no changes needed in Hosts or servers that are connected to them.
The disadvantage is multi-vendor devices might be present in the real SAN networks & not all the vendors implemented in same way.

Fabric Zoning:
It is Network-centric method & basically Switch (or Fabric) present in the SAN networks have the capability to allow grouping of Ports from Storage Sub-systems to Connected Hosts in the form of Zoning.
The disadvantage is that Fabric zoning cannot mask individual LUNs that sit behind a port. All hosts connected to the same port will see all the LUNs addressed through that port.

NOTE:
* Each of these Host-centric, Storage centric & switch-centric methods provide their own benifits & drawbacks.
* Usually to provide very good solution, combination of any two methods will be implemented in real SAN networks.

Storage Subsystems - implementation in SAN

2008-06-04T11:46:00.001+05:30

********If anyone need expert consultation, do send me email at storagetrendz@gmail.com************************

* The storage components of a SAN are the storage arrays. Storage arrays include storage processors (SPs). The SPs are the front end of the storage array. SPs communicate with the disk array (which includes all the disks in the storage array) and provide the RAID/LUN functionality.
* Storage Processors or Controllers:
SPs provide front-side host attachments to the storage devices from the servers, either directly or through a switch. The server HBAs must conform to the protocol supported by the storage processor. In most cases, this is the FC protocol.
* Storage processors provide internal access to the drives, which can be using a switch or bus architecture. In high-end storage systems, drives are normally connected in loops.
* This back-end loop technology employed by the SP provides several benefits:
# High-speed access to the drives
# Ability to add more drives to the loop
# Redundant access to a single drive from multiple loops (when drives are dual-ported and attached to two loops)
* Storage Devices
Data is stored on Hard disk arrays or tape devices (or both).
Disk arrays are groups of multiple disk devices and are the typical SAN disk storage device. They can vary greatly in design, capacity, performance, and other features.
* storage array uses RAID (Redundant Array of Independent Drives) technology to group a set of drives.
* A LUN is a single unit of storage. A LUN is also known as a volume or Virtual Disk or a logical drive, A RAID Group is one or more LUNs with specific RAID level defined.
* Most storage arrays provide additional data protection and replication features such as
snapshots, Clone copies and Remote mirroring.
# A snapshot is a point-in-time copy of a LUN. Snapshots are used as backup sources for the overall backup procedures defined for the storage array.
# Clone copies are actual copy of a LUN, it allows data movement from one LUN to another for an additional copy for testing.
# Remote mirroring provides constant synchronization between LUNs on one storage array and a second, independent (usually remote) storage array for disaster recovery.

Host Bus Adapter [HBA]

2008-05-13T11:51:00.000+05:30

* HBA is an important component of Storage networks, especially in SAN architecture.
* HBA is usually host-side component & can be connected to PCI or PCI-X or PCI-E slots on the host or servers. it provides the crucial connectivity between Hosts-StorageSubsystems in Direct attached setup, provides connectivity between Host-FabricSwitches-StorageSubsystems in SAN environment.
* HBA vendors are very few, some vendors provide HBA management software & drivers along with HBA (ex: Qlogic, Emulex, Brocade etc).
* HBAs available in market may be of Fibre Channel (FC), SCSI, SAS and iSCSI interfaces.
* HBA comes in different priceband and the difference in price band is largely driven by the number of ports. HBAs are available in the market with single port, dual(2) Ports, Quad(4) ports, octa(8) ports etc. Depending on the number of Ports & the type of interfaces, the HBA cost varies from 500$ to 5000$ or even more.

Fabric-side or Switch-side Implimentation in SAN

2008-02-25T17:52:00.001+05:30

For More info & your Feedback, contact Email ID: storagetrendz@gmail.com.

FC SAN:
* FC Switch or Fabric in SAN architecture consists of Ports (GBIC or SFP in it), FC protocol stack, Fabric Operating system & Fabric Controller units.
* The Fabric provides basic functionality of connecting multiple Hosts & Storage Sub systems together and manages the communication between them. using Fabric switch topology, about 16 million devices can be connected together in SAN Network.
* Each port on the Swicth is having Unique Address called as World Wide Node Name (WWWN) & World Wide Port Name (WWPN).
* In addition, Fabric provides advanced functionalities as given below,
1. Multi casting & Broad casting services.
2. Name Server Database services.
3. Login Services.
4. Register state Change Notification [RCN] Services.
* Fabric Zoning is the important feature provided by FC switches, By appropriately creating zones and assigning devices [HOST + storage LUNs], an administrator can create a network in which individual hosts cannot access storage devices that are controlled by another host in the FC network.

iSCSI SAN:
* iSCSI Switch or Ethernet Swicth in SAN architecture consists of Ports (ethernet ports), TCP/IP & iSCSI protocol stack, switch software & Controller units.
* The ethernet iSCSi swith provides basic functionality of connecting multiple Hosts & Storage Sub systems together and manages the communication between them.
* Each port on the Swicth is having Unique Address called as World Wide Unique Identifier (WWUI) & there are three different address format, iqn (iscsi Qualifier Name format by CiSCO), eui (Extended Unique Identifier by IEEE), naa (Network Address Authority by T11 organization).
* In addition, Fabric provides advanced functionalities as given below,
1. Uni-Casting, Multi-casting & Any-casting services.
2. Routing Database services.
3. Login Services.
* VLAN Configuration which is similar to Fabric Zoning in FC SAN.

Note:
* More info. on FC Fabric, Zoning & iSCSI Networking will be published in upcoming Posts.

Host or Server-side Implimentation in SAN

2008-02-08T17:34:00.001+05:30

FC SAN:
* Host or server in SAN architecture consists of HBAs, FC protocol stack, Operating system & Software Applications as shown in the Picture.
* FC Protocol Stack consists of 5 layers (FC0, FC1, FC2, FC3, FC4). each layer corresponds to: physical (FC-0), data link (FC-1, FC-2), network (FC-2, FC-3), and transport (FC-4).
* The SAN storage/disk system is managed by the Host/Server operating system.
Software applications access data via file I/O system calls into the Operating System. The file I/O system calls are handled by the File
System, which manages the directory data structure and mapping from files to disk blocks in an abstract logical disk space.
* The Volume Manager manages the block resources that are located in one or more physical disks in the Disk System and maps the accesses to the logical disk block
space to the physical volume/cylinder/sector address.
* The Fibre Channel protocol stack, ties the Operating System to the Host Bus Adapter(FC HBA) hardware that provides the transport function for block I/O commands to the remote
disk systems across the SAN network.
* The file level I/O initiated by the Software application (SAN management S/W) is mapped into block level I/O by the FC protocol stack & FC interface between the Host/Server and the disk system (Storage Subsystems).
* Fibre Channel is the first network architecture to enable block level storage networking applications.

iSCSI SAN:
* The Host/Server-side implementation is essentially the same as the Fibre Channel SAN. The key difference here is that the Fibre Channel protocol stack & FC Interfaces (FC-HBA, Cables, connectors, Network components) is
replaced by the iSCSI/TCP/IP stack & Ethernet (TCP/IP) Interfaces (iscsi-HBA, Cables, connectors, Network components).
* In FC based SAN, FC protocol stack maps the Block level (I/O) SCSI commands into Fibre Channel Frames & carries SCSI data over FC to remote storage subsystems in SAN envirnoment.
* In iSCSI based SAN, iSCSI/TCP/IP stack maps the Block level (I/O) SCSI commands into TCP/IP Data packets & carries SCSI data over Ethernet to remote storage subsystems in SAN envirnoment.

NOTE: the Picture posted with this topic shows interesting comparison of Host or Server-side Implementation in DAS, SAN (FC & iSCSI) and NAS.

Storage Area Networking [SAN] Components

2008-01-07T19:07:00.001+05:30

While SAN Infrastructure & configurations can become very complex, a simple SAN setup includes three basic entities;

the host system or systems, the network and the storage devices.
1. Host or Server System(s):
• Application Software (e.g., SAN Management software)
• Middleware (e.g., Volume Manager or Host RAID)
• Operating System/File System
• Host Bus Adapter (HBA) Driver
• Host Bus Adapter (HBA)
• Host Bus Adapter Firmware
2. Storage Network/Communications Infrastructure:
• Physical Links
• Transceivers (e.g. SFPs)
• Switches and Switch Firmware
• Routers and Router Firmware
• Bridges or Extenders and their Firmware
• SAN Cables & Connectors
3. Storage Device(s)or Sub systems
• Interface Adapter
• Interface Adapter Driver/Firmware
• Storage Controller Firmware
• Storage Device (e.g., disk or tape)
• Storage Media

Note:
* Fibre Channel protocol based SAN (FC SAN) consists of Hosts with FC HBAs, FC Switches, FC Hubs, FC Routers, FC cables & Connectors and FC based Storage devices.
* Internet Protocol based SAN (iscsi SAN) consists of Hosts with iSCSI HBAs, Ethernet Switches, Ethernet Routers,Ethernet cables & Connectors and iSCSI based Storage devices.

SAN Introduction

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* SAN is the network between Storage devices & Host/servers, designed & implemented to provide pool of Storage resources mainly to fulfill the exponential need of storage backbone for small & medium offices, Mid-range & large Enterprises Using Fibre Channel or iSCSI Technologies.
* SAN provides block-orient I/O between the Server systems and the target storage systems, in comparison of NAS that gives File-oriented I/O.
* In comparison to DAS & NAS, SAN provides High availability of storage resources, more Secure & Reliable, Cost effective, reduced Downtime, secured Backup storage solutions.
* SAN is designed & implimented using either robust Fibre Channel Technology (FC SAN) or evergreen Internet Protocol Technology (iSCSI SAN). might be using both in near future.
* The SAN is often built on a dedicated network fabric that is separated from the LAN network to ensure the latency-sensitive block I/O SAN traffic does not interfere with the traffic on the LAN network.
* Even when iSCSI SAN runs over Ethernet technology, the SAN may still be separated from the LAN either physically, or logically via VLAN to ensure the security and the QoS on the SAN traffic.
* SAN storage devices are specifically designed as stand alone devices that can communicate with the Servers or hosts of different server vendors, Operating system vendors, Host adapter vendors, Switch vendors.
* SAN Architecture, accommodates DAS Implemented setups within its infrastructure & hence, DAS & SAN setups will co-exist in the same SAN infrastructure & also allows Enterprises to migrate from existing DAS setups to newer SAN setups & implementations.
* SAN Islands, implemented in different geographical locations can communicate using gateway devices such as FCIP based gateway, iFCP based gateway & iSCSI based gateway.

Storage Networks - FAQs

2007-12-21T12:24:00.001+05:30

* What Is a Storage Network?
Storage Nework Is the networking of Storage devices & Host/servers, designed & implimented to provide pool of Storage resources mainly to fullfill the exponential need of storage backbone for small & medium offices, Mid-range & large Enterprises.
in other words any network designed to provide Storage solutions to the perticular organizations.

* What are the main technical architectures a storage network may comprise of?
A typical Storage Network may comprises of one or many of the following architectures designed & implimented;
* Direct Attached Storage Architecture (DAS)
* Storage Area Network Architecture (SAN)
* Network Attached Storage Architecture (NAS)

What are the main Physical Components of DAS in storage network?
* SCSI based DAS: Host/Servers, SCSI HBAs/RAID Controllers, SCSI Storage Subsystems (Disks & JBOD).
* SATA based DAS: Host/Servers, SATA HBAs/RAID Controllers, SATA Storage Subsystems (Disks & JBOD).
* SAS based DAS: Host/Servers, SAS HBAs/RAID Controllers, SAS Storage Subsystems (Disks & JBOD).
* FC based DAS: Host/Servers, FC HBAs/RAID Controllers, FC Storage Subsystems (JBOD).

What are the main Physical Components of SAN in storage network?
* FC based SAN: Host/Servers, FC HBAs, FC Switches, FC Storage Subsystems, SFPs/GBICs, FC Cables & Connectors.
* iSCSI based SAN: Host/Servers, iSCSI HBAs, Ethernet Switches, iSCSI Storage Subsystems, ethernet Cables & Connectors.

What are the main Physical Components of NAS in storage network?
* Ethernet/NIC, ethernet Switches, NAS Filers or Appliances (storage subsystems).
* Software File system is important component in NAS & CIFS is used for Windows, NFS is used for Unix flavours.

List some of the advanced storage technologies being designed & implimented currently relevent to Storage Networks?
* SAS Technology - mainly as Drive-side interface for Hard disks, Enclosure/JBODs & storage subsystems(used in SAN). Complimentory to SCSI technology.
* iSCSI Technology - mainly designed as Network-side & Host-Side transport media and connectivity. Complimentory to Fibre Channel technology (FC) in SAN architecture.
* Virtualization Technology - Mainly virtualizing every possible physical resources into logical resources in Storage Networks.
Note:- Host-based Virtualization (ex: Xensource, VMWARE), Network-based Virtualization (ex: SVM appliance), Storage-Based Virtualization (ex:Snap copy, Mirror copy).
* Infiniband technology - entirely new I/O architecture, new standards based & predicted as the most dominent Storage technology in the future.
* FCOE Technology - Mainly Fibre Channel Over Ethernet (FCOE) technology, expected to be complimentory technology to SAN Architecture.
* other Technologies.

Do you think diverse multiple technology in Storage networks leads to confusion to customers?
* yes, Because customer's need for storage infrastructure may not be fulfilled by any perticular technology & Customer might end up with wrong selections due to confusion.
* yes, Because Customer might not be having enough knowledge of different available technologies & customer might end up selecting insufficient technology due to technical limitations of specific technology.
* No, Because Customer with enough storage knowledge will have multiple solutions/options to fulfill his needs by using diverse technologies.
* No, Because Diverse multiple technologies compete each other in terms of providing Cost effective solutions & inturn reduces customer's expenditure on storage infrastracture.
Hence, i belive its better to have multiple solutions rather than not having solutions.

Direct Attached Storage Components:

2007-12-11T19:59:00.001+05:30

For expert consultation contact Mail ID: storagetrendz@gmail.com

What are the Components need for DAS Setup?
* Host or Sever with PCI or PCI-X or PCI-E slots.
* RAID Controller(one or more) gets connected to any of PCI slots depending on the card support.
* Connectors & Cables depending on the type of interfaces SATA, SCSI, SAS, FC or IDE.
* Firmware for the Controller.
* Operating systems (Windows or Linux or Solaries flavours)
* Driver for the Controller depending on the OS.
* RAID Controller Management software as per the vendor.
* Storage subsystems, Indivisual Drives or Enclosure/Drive tray with drives.

What is FIRMWARE?
Firmware is a combination of software and hardware. Computer chips that have data or programs recorded on them are firmware. These chips commonly include the following:
* ROMs (read-only memory)
* PROMs (programmable read-only memory)
* EPROMs (erasable programmable read-only memory)

How do we upgrade or downgrade Firmware?
Firmwares for controller cards will be available in the respective vendor websites.
Firmware upgrade/Downgrade can be done using specific Utilities or third party tools as specified by the vendor.

Outline the Configurations supported by RAID controller cards in DAS?
* Logical drive creation/deletion/modification:
Using one or more drives connected to RAID controller card, can create Logical drives according to the RAID level (RAID0,1,3,5,6,10,50 etc.) choosen.
LD configuration created can be removed at any point of time by deletion options. the LD properties such as Stripe size, cache size, rebuild rate, Initialization rate etc can be modified for the specific LD configurations.
Modification to Logical drive properties depends on the Vendor support.
* Syncronization or Initialization:
Usually when new LD is created, Syncronization starts automatically, it is much like formating process but syncronization erases the previous data & add 0's to all the sectors of the Logical drives.
Initialization can be done manually on the existing LD, whenever you like to erase the old data on the LD, initialization can be started.
Fast initialization options erases only the Mettadata information of the LD, not entire LD data & hence it is fast initialization.
Full initialization options erases all data present on the entire LD & hence it is slow process takes hours depending on the LD configuration & Implementation.
* Rebuild Logical Drive:
Rebuild of Logical drive starts due to redundancy feature of RAID, whenever any drive fails within redundant Logical drives, upon insertion of new drive Rebuilding of data takes place & it takes hours to rebuild data depending on the RAID level & properties of specific LDs.
* RAID Level Migration:
Some cards support RAID level Migration but not all the raid levels can be changed to each other, for example RAID1 (2 drives) can be migrated to RAID5 (3 drives) but RAID0 (2drives) cannot be migrated to RAID1(2drives), limitation is total storage capacity which is more in RAID0(2drive) than RAID1(2drives).
Also, it depends on the Vendor implimentations (see picture).
* Reconstruction:
Logical Drive data reconstruction happens for 2 reasons;
>> when Logical drive capacity is expanded (increased), for example: Old Raid config RAID1 with say 20 GB was configured &80 GB remained unused, can be increased upto the free capacity available in the specific raid config(80GB in this example).
>> When RAID Level Migration is started.
* HotSpare:
Some RAID cards allow user to assign unused drive as Hotspare. after configuration Hotspare will remain in standby mode, if any drive fails in Redundent array hotspare will automatically act as replacement drive for failed drive.
main use of the Hotspare is elimination of manual action of removing failed drive & inserting new drive to specific RAID config.
Vendors provide Local Hotspare (assigned to specific Raid config, work for only the Raid config to which it is assigned) & Global Hotspare (can get assigned to any of raid config within storage subsystem, acts on first come first serve basis).

For expert consultation contact Mail ID: storagetrendz@gmail.com

Direct Attached Storage -DAS

2007-11-16T18:59:00.000+05:30

For expert consultation contact Mail ID: storagetrendz@gmail.com

DAS is Direct Attached Storage, as the name suggests, the Storage devices such as Hard drive,Tape drive, Tape Library, JBOD/Enclosure, Storage arrays are directly connected to the Server or Host systems.The simplest example of DAS is the internal hard drive of a server computer.
DAS environment can have one or multiple servers and associated Storage devices. hence Storage resources are dedicated to specific servers and cannot be shared.
in DAS, the main interfaces are Drive-side interfaces & Host-side interfaces and underlying interface technologies are ATA/IDE, SATA, SCSI, SAS and Fiber Channel.
Advantages:
Simple to design & Implement and good option for very small to medium business companies.

Disadvantages:
Direct-attached storage can be more expensive to manage because you cannot redeploy unused capacity, which results in underutilization.
• Having storage distributed throughout the organization makes it difficult to get a consolidated view of storage across the organization.
• Disaster recovery scenarios are limited because a disaster will cause both server and storage outages.
• For data backup and recovery, you need to choose whether to attach local backup devices to each server, install dual network adapters in each server and back up the data over a separate LAN, or back up the server over the corporate LAN.
Large organizations have found that placing stand-alone tape drives in individual servers can quickly become expensive and difficult to manage, especially when the number of servers in the organization grows into the hundreds.
In this situation, it is often best to back up servers over a network to a storage library, which offers backup consolidation and eases management.
For expert consultation contact Mail ID: storagetrendz@gmail.com