CentOS / RHEL / Fedora

If you cannot access your hard drive try this tip :

2014-08-09T13:17:00.000+04:00

This small command save my 900GB.

Run Check Disk from the Command Line to Find and Fix Errors

You can run Check Disk from the command line or within other utilities. At a command prompt, you can test the integrity of the L drive by typing the following command:

chkdsk L:

To find and repair errors that are found in the L drive, use the following command:

chkdsk /f L:

Note that Check Disk can’t repair volumes that are in use. If the volume is in use, Check Disk displays a prompt that asks if you want to schedule the volume to be checked the next time you restart the system. Click Yes to schedule this.

The complete syntax for Check Disk is this:

chkdsk [volume[[path]filename]]] [/F] [/V] [/R] [/X] [/I] [/C] [/L[:size]]

The options and switches for Check Disk are used as follows:
Volume Sets the volume to work with.
filename FAT/FAT32 only: Specifies files to check for fragmentation.
/F Fixes errors on the disk.
/V On FAT/FAT32, this displays the full path and name of every file on the disk. On NTFS, this displays cleanup messages, if any.
/R Locates bad sectors and recovers readable information (implies /F).
/L:size NTFS only. Changes the log file size.
/X Forces the volume to dismount first if necessary (implies /F).
/I NTFS only. Performs a minimum check of index entries.
/C NTFS only. Skips checking of cycles within the folder structure

copy from microsoft technet.

How do I sync folders/files between my PC and my external drive

2014-07-06T18:03:00.001+04:00

SyncToy 2.1 is a free application that synchronizes files and folders between locations. Typical uses include sharing files, such as photos, with other computers and creating backup copies of files and folders.

Free Microsoft Download

100+ Usefull Run Commands List

2013-06-28T11:55:00.000+04:00

Accessibility Options : access.cpl

Add Hardware : hdwwiz.cpl

Add / Remove Programs : appwiz.cpl

Administrative Tools : control admintools

Automatic Updates : wuaucpl.cpl

Wizard file transfer Bluethooth : fsquirt

Calculator : calc

Certificate Manager : certmgr.msc

Character : charmap

Checking disk : chkdsk

Manager of the album (clipboard) : clipbrd

Command Prompt : cmd

Service components (DCOM) : dcomcnfg

Computer Management : compmgmt.msc

DDE active sharing : ddeshare

Device Manager : devmgmt.msc

DirectX Control Panel (if installed) : directx.cpl

DirectX Diagnostic Utility : dxdiag

Disk Cleanup : cleanmgr

System Information : dxdiag

Disk Defragmenter : dfrg.msc

Disk Management : diskmgmt.msc

Partition manager : diskpart

Display Properties : control desktop

Properties of the display (2) : desk.cpl

Properties display (tab "appearance") : control color

Dr. Watson : drwtsn32

Manager vérirficateur drivers : check

Event Viewer : Eventvwr.msc

Verification of signatures of files : sigverif

Findfast (if present) : findfast.cpl

Folder Options : control folders

Fonts (fonts) : control fonts

Fonts folder windows : fonts

Free Cell : freecell

Game Controllers : Joy.cpl

Group Policy (XP Pro) : gpedit.msc

Hearts (card game) : mshearts

IExpress (file generator. Cab) : IExpress

Indexing Service (if not disabled) : ciadv.msc

Internet Properties : inetcpl.cpl

IPConfig (display configuration) : ipconfig / all

IPConfig (displays the contents of the DNS cache) : ipconfig / displaydns

IPConfig (erases the contents of the DNS cache) : ipconfig / flushdns

IPConfig (IP configuration cancels maps) : ipconfig / release

IPConfig (renew IP configuration maps) : ipconfig / renew

Java Control Panel (if present) : jpicpl32.cpl

Java Control Panel (if present) : javaws

Keyboard Properties : control keyboard

Local Security Settings : secpol.msc

Local Users and Groups : lusrmgr.msc

Logout : logoff

Microsoft Chat : winchat

Minesweeper (game) : winmine

Properties of the mouse : control mouse

Properties of the mouse (2) : main.cpl

Network Connections : control NetConnect

Network Connections (2) : ncpa.cpl

Network configuration wizard : netsetup.cpl

Notepad : notepad

NView Desktop Manager (if installed) : nvtuicpl.cpl

Manager links : packager

Data Source Administrator ODBC : odbccp32.cpl

Screen Keyboard : OSK

AC3 Filter (if installed) : ac3filter.cpl

Password manager (if present) : Password.cpl

Monitor performance : perfmon.msc

Monitor performance (2) : perfmon

Dialing Properties (phone) : telephon.cpl

Power Options : powercfg.cpl

Printers and Faxes : control printers

Private Character Editor : eudcedit

Quicktime (if installed) : QuickTime.cpl

Regional and Language Options : intl.cpl

Editor of the registry : regedit

Remote desktop connection : mstsc

Removable Storage : ntmsmgr.msc

requests the operator to removable storage : ntmsoprq.msc

RSoP (traduction. ..) (XP Pro) : rsop.msc

Scanners and Cameras : sticpl.cpl

Scheduled Tasks : control schedtasks

Security Center : wscui.cpl

Console management services : services.msc

shared folders : fsmgmt.msc

Turn off windows : shutdown

Sounds and Audio Devices : mmsys.cpl

Spider (card game) : spider

Client Network Utility SQL server : cliconfg

System Configuration Editor : sysedit

System Configuration Utility : msconfig

System File Checker (SFC =) (Scan Now) : sfc / scannow

SFC (Scan next startup) : sfc / scanonce

SFC (Scan each démarraget) : sfc / scanboot

SFC (back to default settings) : sfc / revert

SFC (purge cache files) : sfc / purgecache

SFC (define size CAHC x) : sfc / cachesize = x

System Properties : sysdm.cpl

Task Manager : taskmgr

Telnet client : telnet

User Accounts : nusrmgr.cpl

Utility Manager (Magnifier, etc) : utilman

Windows firewall (XP SP2) : firewall.cpl

Microsoft Magnifier : magnify

Windows Management Infrastructure : wmimgmt.msc

Protection of the accounts database : syskey

Windows update : wupdmgr

Introducing Windows XP (if not erased) : tourstart

Wordpad : write

Date and Time Properties : timedate.cpl

Download full Commands List

How to Cable an EMC VNXe for Failover & VMWare

2013-06-22T09:40:00.001+04:00

I really struggled with cabling a new VNXe for failover with vSphere. It's not difficult. There's just not a lot of documentation or explanation out there for it. The best practices docs and howtos treat iSCSI like a 3rd class citizen and assume you'd really rather be using Fiber or NFS. So here's how you really do it and a little explanation about why. We'll go into the details of the vSphere configuration after covering the hardware end of things.

Read Full Story

PFSense – An Awesome Firewall

2013-06-11T14:22:00.000+04:00

pfSense is an open source firewall/router distribution based on FreeBSD. pfSense is meant to be installed on a personal computer and is noted for its reliability and offering features often only found in expensive commercial firewalls. It can be configured and upgraded through a web-based interface, and requires no knowledge of the underlying FreeBSD system to manage. pfSense is commonly deployed as a Perimeter Firewall, router, wireless access point, DHCP server, DNS server, and as a VPN endpoint.

The name was derived from the fact that it helps make the OpenBSD packet-filtering tool pf make more sense to non-technical users.

PFSense Download : http://mirror.myip.be/pub/pfsense/downloads/
Full Installation Guide : http://www.impromptu-it.com/?p=179

How to delete partition on usb thumb drive

2013-06-03T12:59:00.003+04:00

From Command prompt type diskpart

Within Diskpart, use the List Disk command to check which disk the USB device is. The USB device should be obvious; in my case, it's the 14GB disk.

DISKPART> list disk

Disk ### Status Size Free Dyn Gpt
-------- ------------- ------- ------- --- ---
Disk 0 Online 465 GB 1024 KB
Disk 1 Online 14 GB 0 B

Once the disk is known, select the disk and run the rest of the displayed commands (change "disk 1" to the number of your disk):

DISKPART> select disk1

Disk 1 is now the selected disk.

Clean the partition

DISKPART> clean

DiskPart succeeded in cleaning the disk.

ESXi-Customizer

2013-06-01T20:12:00.003+04:00

ESXi-Customizer is a Windows script that automates the process of re-building the VMware ESXi Install ISOs with custom drivers.

Download : ESXi-Customizer-v2.7.1

Cisco 1751V password recovery

2013-03-13T20:38:00.001+04:00

When i try to login my cisco 1751V router. Unfortunately, I didn’t receive the credentials to log on to the router. As a ‘note to self’: here comes the password recovery procedure for a 1751V.

Turn the power on.
Press the ‘break’ key within 60 seconds (in putty, I needed to use CTRL-Break). You should get to the rommon prompt:

rommon 1 >

Change the configuration register so the router will ignore the existing config (this 0x setting can vary):

rommon 1 > confreg 0x142

Next, reset the router:

rommon 2 > reset

Once the router has restarted, it will ask you if you would like to enter the initial configuration dialog. There you go. You now have two options:

Copy the startup-config to running-config and change the password for any username that exists in the startup-config.
Just start from scratch.

Since I just wanted to start from scratch, I was ready to go from there.

Synchronizing ESX/ESXi time with a Microsoft NTP Server

2013-01-28T11:00:00.001+04:00

An ESX or ESXi host configured to use a Microsoft Windows or newer Domain Controller as a time source never synchronizes its clock with a default configuration.follow this steps to setup correct sync.

Download NTP server and support details
http://www.4shared.com/rar/69DxFWGw/NTP_Settings.html

VMware vSphere ESXi 5.0, 5.1 - Installation from PXE Boot

2013-01-28T10:51:00.001+04:00

A small tool for deploying VMware ESXi from another computer running with Microsoft Windows.

Download Tool
http://www.4shared.com/rar/1CcYk0zr/New_folder.html

What’s New in VMware vSphere 5.1?

2012-09-11T20:13:00.001+04:00

vSphere 5.1 is VMware’s latest release of its industry-leading virtualization platform. This new release contains the following new features and enhancements:

Compute

• Larger virtual machines – Virtual machines can grow two times larger than in any previous release to support even the most advanced applications. Virtual machines can now have up to 64 virtual CPUs (vCPUs) and 1TB of virtual RAM (vRAM).

• New virtual machine format – New features in the virtual machine format (version 9) in vSphere 5.1 include support for larger virtual machines, CPU performance counters and virtual shared graphics acceleration designed for enhanced performance.

Storage

• Flexible, space-efficient storage for virtual desktop infrastructure (VDI) – A new disk format enables the correct balance between space efficiency and I/O throughput for the virtual desktop.

Network

• vSphere Distributed Switch – Enhancements such as Network Health Check, Configuration Backup and Restore, Roll Back and Recovery, and Link Aggregation Control Protocol support and deliver more enterprise-class networking functionality and a more robust foundation for cloud computing.

• Single-root I/O virtualization (SR-IOV) support – Support for SR-IOV optimizes performance for sophisticated applications.

Availability

• vSphere vMotion® – Leverage the advantages of vMotion (zero-downtime migration) without the need for shared storage configurations. This new vMotion capability applies

to the entire network.

• vSphere Data Protection – Simple and cost effective backup and recovery for virtual machines. vSphere Data Protection is a newly architected solution based EMC Avamar technology that allows admins to back up virtual machine data to disk without the need of agents and with built-in deduplication. This feature replaces the vSphere Data Recovery product available with previous releases of vSphere.

• vSphere Replication – vSphere Replication enables efficient array-agnostic replication of virtual machine data over the LAN or WAN. vSphere Replication simplifies management enabling replication at the virtual machine level and enables RPOs as low as 15 minutes.

• Zero-downtime upgrade for VMware Tools – After you upgrade to the VMware Tools available with version 5.1, no reboots will be required for subsequent VMware Tools upgrades.

Security

• VMware vShield Endpoint™ – Delivers a proven endpoint security solution to any workload with an approach that is simplified, efficient, and cloud-aware. vShield Endpoint enables 3rd party endpoint security solutions to eliminate the agent footprint from the virtual machines, offload intelligence to a security virtual appliance, and run scans with minimal impact.

Automation

• vSphere Storage DRS™ and Profile-Driven Storage – New integration with VMware vCloud® Director™ enables further storage efficiencies and automation in a private cloud environment.

• vSphere Auto Deploy™ – Two new methods for deploying new vSphere hosts to an environment make the Auto Deploy process more highly available then ever before. Management (with vCenter Server)

• vSphere Web Client –The vSphere Web Client is now the core administrative interface for vSphere. This new flexible, robust interface simplifies vSphere control through shortcut navigation, custom tagging, enhanced scalability, and the ability to manage from anywhere with Internet Explorer or Firefox-enabled devices.

• vCenter Single Sign-On – Dramatically simplify vSphere admin- istration by allowing users to log in once to access all instances or layers of vCenter without the need for further authentication.

• vCenter Orchestrator – Orchestrator simplifies installation and configuration of the powerful workflow engine in vCenter Server. Newly designed workflows enhance ease of use, and can also be launched directly from the new vSphere Web Client.

Learn More

For information on upgrading to vSphere 5.1, visit the vSphere Upgrade Center at http://www.vmware.com/products/vsphere/upgrade-center/overview.html.

vSphere is also available with the new vCloud suites from VMware. For more information, visit http://www.vmware.com/go/vcloud-suite/.

Installing a driver in an existing VMware vSphere 4.1 ESX/ESXi host

2012-09-07T09:20:00.000+04:00

We recently purchased some new "Intel Eth QP Ser Adapter T4" cards for our existing VMware ESX 4.1 hosts. The card has four ports, each capable of transmitting one Gbps each.
Unfortunately, the driver for this card isn’t in the default set installed with VMware vSphere. Like all things VMware, getting these to work in an existing host is not the easiest of things. During ESX installation, a big glaring warning message is displayed: “If you choose to not install additional drivers at this time, you will not be able to do so later.” Well, that’s not exactly true. To work around this, just follow the instructions below.

Verify that the card is supported by the VMware HCL.
Download the driver from VMware’s Driver CD Repository.
Put your ESX/ESXi host into maintenance mode.

At this point, you can install additional drivers one of two ways: via the vSphere CLI, where you run the files from your own workstation, or via the esxupdate command on the ESX host itself. I personally prefer to do it via the vSphere CLI.

1. If you haven’t already installed the vSphere CLI, you can get it at VMware.
2. Burn the downloaded ISO to a CD and leave it inserted in your drive.
3. Open a command prompt at “C:\Program Files (x86)\VMware\VMware vSphere CLI\bin” (assuming you are using an x64 flavor of Windows).
4. Use the vihostupdate Perl script as shown: vihostupdate.pl –server <IP Address of host> -username root –install –bundle <path to offline bundle> The “path to offline bundle” is much like what was used in the other option, but it just looks at your local drive. An example would be “D:\offline-bundle\driver.zip”.

vihostupdate.pl --server 192.168.123.10 --username root --install --bundle D:\offline-bundle\driver.zip

Source : http://4sysops.com

Download CentOS 6.3 CD / DVD ISO

2012-08-22T09:21:00.002+04:00

We are pleased to announce the immediate availability of CentOS-6.3
for i386 and x86_64 Architectures. Release Notes for 6.3
are available at http://wiki.centos.org/Manuals/ReleaseNotes/CentOS6.3 -
we recommend everyone looks through those once.

CentOS-6.3 is based on the upstream release EL 6.3 and includes packages
from all variants. All upstream repositories have been combined into
one, to make it easier for end users to work with.

All updates released since upstream 6.3 release are also released to the
CentOS-6.3 mirrors.

Downloading CentOS-6.3 for new installs:

When possible, consider using torrents to run the downloads. Usually its
also the fastest means to download the distro.

Torrent files for the DVD's are available at :
http://mirror.centos.org/centos/6.3/isos/i386/CentOS-6.3-i386-bin-DVD1to2.torrent
http://mirror.centos.org/centos/6.3/isos/x86_64/CentOS-6.3-x86_64-bin-DVD1to2.torrent

You can also use a mirror close to you :
http://www.centos.org/modules/tinycontent/index.php?id=30

Most mirrors will allow direct DVD downloads over http, ftp and rsync.

Please keep in mind that not all mirrors are currently updated, some
might take upto another 24 hours before they have all the content.

We have also made efforts to try and ensure that most install types and
roles can be run from DVD-1 itself.

Enable SNMP on ESXi 5.o

2012-07-27T22:21:00.004+04:00

use Putty to connect to your host or use the ESXi console.
cd to vmware folder : cd /etc/vmware/
do and ls you will see your beast snmp.xml here

Edit the file using vi
vi snmp.xml
you will see a single line. press i to enter the edit mode.

we need to change false to true and add Public between <communities></communities>

once happy with this, Press Esc and the :wq to save and quit.
we will have to restart the services.sh under /sbin/ folder with /sbin/services.sh restart
you should now be able to use any monitoring software to monitor your hosts.
Enjoy.

source : http://vm-blog.info

IBM Bootable Media Creator (BoMC)

2012-07-20T21:12:00.002+04:00

You can use IBM ToolsCenter Bootable Media Creator to create bootable media that is suitable for applying firmware updates, running preboot diagnostics, and deploying Microsoft Windows operating systems on supported systems.
IBM System x and BladeCenter tools each have their own bootable CD. Using IBM ToolsCenter Bootable Media Creator, you can create a single bootable image on supported media (such as CD, DVD, ISO image, USB flash drive, or set of PXE files) that bundles multiple IBM System x and BladeCenter tools and updates from UpdateXpress System Packs, which contain Windows and Linux firmware and device driver updates. You can also create an IBM ServerGuide Setup and Installation CD for deploying Windows operating systems and updates on supported systems.

Introducing Cisco Connect Cloud !

2012-07-16T20:19:00.001+04:00

Now available for Linksys Smart Wi-Fi Routers, Cisco Connect Cloud gives you anytime, anywhere access to your home network.
This revolutionary new technology delivers a host of free apps for your router, and that's only the beginning. As new devices and ways of interacting with your home emerge, Cisco Connect Cloud will keep expanding with new apps to enrich your connected lifestyle.

More Info

How to: Add iSCSI SAN storage to VMWare ESXI

2012-07-14T19:29:00.001+04:00

In this Tutorial I am gong to show you how to add a LUN on a SAN through the iSCSI initiator on VMWARE ESXI Server.
The SAN I had available to do this on, is the Promise VessRAID 1830i
NOTE: Your interface to your SAN might look different, but the terminology stays the same.
1. Creating the storage LUN on the SAN�
Login to your SAN interface, and create a new logical drive / LUN (whatever your SAN calls it)

For the purpose of the tutorial, I created a LUN of 500GB in space, in RAID 5 configuration.

My SAN asks if I want to edit lun mapping (Masking), once a LUN is configured. I always mask luns, as I want devices to only see the LUNs they are entitled to. I clicked “OK”

Next I selected my iSCSI initiator (Shown later in post), and gave the LUN I just created an ID of 0, as this is the first LUN that I am assigning to my ESXI server.

And once I submitted my changes, my SAN is all setup and ready to go.

2. Adding the LUN to ESXI

Now, open your vSphere client, and login to your ESXI host. On the main page, click on your “Congifuration” tab, then click “Storage Adapters”

Your first item will be the iScsi initiator. Select it, and click on “Properties” in the below section

You will first need to enable your iScsi initiator. To do this, click “Configure” in the properties dialog.

Check the “Enable” tickbox, and in the iSCSI Name field, you will see the name of the iSCSI initiator (Which you will use on your san for LUN masking) and click “Ok”

On the next Tab (Dynamic Discovery), click on “Add” and enter the IP address of one of your iSCSI ports of your san, mine is 10.1.1.27

Click “Ok” and then “Close” the properties window.
Once this is done, vSphere will prompt you to rescan the iSCSI host for any new luns available, click “Yes”

Once the adapter is rescanned (Takes a couple of seconds), your LUN will be shown in the list view below.
The reason I am only seeing the 500GB LUN I Created, is because I use LUN Masking on my SAN, thus making only the created LUN available to the ESXI iSCSI initiator.

Now, your SAN LUN is Added to ESXI. Only config left is to tell ESXI what to use the new storage for.
Click on “Storage” on the left menu in the “Hardware” section, where you will see it displays my current local datastore which is only the local harddrives. Click on “Add Storage”

In the Add Storage wizard first page, select “Disk/LUN” and click Next

Your Added LUN will be in the list, select it, and click “Next”

Next will be a summary of your disk layout, click next
(NOTE: If you get an error when this page loads, it will probably be because there is a SAN operation running on the LUN like Initialization, Syncing, capacity expansion, etc – all in all, if you get an error here, your LUN isn’t ready on the san)

Next enter a name for the LUN (Just so you can identify it)

On the next page you will see the file formatting config, I left the defaults, and clicked next

You will get a final summary page to confirm everything, click “Finish”

Once you have successfully finished the wizard, you will see your LUN storage ready in the storage list.

Now when you create a new VM, you will see the new storage on your san in the Datastore step of the create VM Wizard.

And of course, when adding a new hard drive on a VM.

Final Word:
It is really really easy to add a SAN as a storage location for your VMs in ESXI, the Promise VessRAID range is an affordable SAN solution for small businesses and I would recommend this to any company that would like to enter the SAN arena for little cost. The Promise VessRAID 1830i will cost you around $250 with disks unpopulated.

Source : http://www.tjopsta.net

Converting A VMware Image To A Physical Machine

2012-04-30T07:11:00.001+04:00

This tutorial shows how to convert an existing CentOS VM to a Physical machine. This tutorial covers the cloning of the VM to an unpartitioned HDD and troubleshoot some of the possible errors that you may have booting the OS on your new hardware. To illustrate this procedure I will use VMware Workstation 7 as the handler to transfer the VM installation to a physical HDD.

1 Requirements

To perform this procedure you will need:

VMware Workstation, VMware Server or VMware Player.
CloneZilla ISO image.
Unpartitioned HDD with enough space to hold your VM image.

2 Preliminary Notes

This tutorial assumes basic knowledge of the cloning process and requires no previous experience on the use of Clonezilla. Make sure your OS is not using in any way the target HDD that will hold your final copy of the VM, otherwise VMware will complain about your disk been in use and CloneZilla will not perform a successful copy of the VM.

3 VMware Configuration

First thing is to make sure your virtual CD/DVD is using your CloneZilla ISO image to boot. Next add your physical HDD as part of your existing VM by clicking the Add button.

Select Hard Drive and click Next.

Select Use physical disk (for advanced users) then click Next.

Make sure you select the correct drive that you want to use for your physical disk and select the option Use entire disk.

Finally give a name to your configuration file then click Finish.

Make sure your final VMware hardware list include this two elements otherwise, start all over.

4 CloneZilla Cloning Process

Start your VMware and boot from your virtual ISO into CloneZilla image. Use the Live option with default settings.

Select your preferred language and continue.

Accept the default option Don't touch keymap and continue.

Select Stat_clonezilla and continue.

Select device-device option and continue.

Select Beginner mode and continue.

Select disk to local disk and continue.

Select your source disk and click OK.

Select your target disk and click OK, then press Enter to continue.

You will be presented with a warning, about your existing data on your target disk will be lost, make sure there's nothing usable on your disk before you continue.

You will be presented with a series of questions answer yes to all this prompts.

The cloning process may take a long time.

After the cloning process is finished hit Enter and power off the VM by pressing 0 on the CloneZilla menu.

The cloning process is complete, is now time to install your new HDD to your physical machine.

5 Troubleshooting Physical Machine

More likely your first encounter with your cloned OS will be a filesystem corruption, with the following error: Unexpected Inconsistency. To fix this problem enter your root password and run fsck -y to start the filesystem repair process. The -y answers yes to the questions the fsck command will probably output.

Your next challenge will be fixing your NIC, I have used two different methods to fix this problem.

Go into /etc/udev/rules.d and delete the file 70-persistent-net.rules then reboot. Deleting the file forces the detection process to run again at boot with no baggage left over from the cloning process.

The other way to fix this problem is by edit: /etc/sysconfig/network-scripts/ifcfg-eth0 and add the MAC address of your new NIC.

Open eth0 using vi, type:

vi /etc/sysconfig/network-scripts/ifcfg-eth0

Edit the following line:

HWADDR=<MAC address of the network interface>

This is my sample config file:

# Micro-Star INT'L CO Gigabit Ethernet Controller
DEVICE=eth0
BOOTPROTO=static
DHCPCLASS=
HWADDR=00:19:B1:2A:BA:B8
IPADDR=10.10.11.50
NETMASK=255.255.255.192
ONBOOT=yes

Save and close the file then reboot the server:

reboot

The system is now ready to be used.

6 Links

CloneZilla: http://clonezilla.org/

Formatting USB Flash Drive on Linux

2012-04-15T07:16:00.002+04:00

Under UNIX-like operating systems, formatting a USB flash drive, in fact even a hard drive, requires knowing the file name for the partition that is to be formatted. These are files under the /dev directory, like for example, /dev/sdb1. So the interesting question to be asked is how does one come to know of the file representing the partition on the device? Immediately after connecting a USB flash drive to my laptop running Arch Linux and looking at the last few lines of ‘dmesg’ output gives:

sd 4:0:0:0: [sdb] 31703040 512-byte logical blocks: (16.2 GB/15.1 GiB)

Notice the ‘sdb’ within square brackets. This hints that the device file would start with /dev/sdb. Further, running:

$ ls -l /dev/sdb*
brw-rw---- 1 root disk 8, 16 Jan 31 23:55 /dev/sdb
brw-rw---- 1 root disk 8, 17 Jan 31 23:49 /dev/sdb1

And keeping it mind that it is a partition that is formatted, confirms the file that we are searching to be /dev/sdb1. Now, for formatting, if it is the EXT4 filesystem that is to be built then run:

mkfs.ext4 -L <label> /dev/sdb1

Use of the -L <label> switch is optional. It gives a fancy name to the device that is often visible when automounting in a desktop environment like KDE or GNOME. After the above commands successful termination, one might want to print the partition table on the device for assurance:

# parted /dev/sdb print
Model: JetFlash Transcend 16GB (scsi)
Disk /dev/sdb: 16.2GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number  Start   End     Size    Type     File system  Flags
1      16.4kB  16.2GB  16.2GB  primary  ext4         boot, lba

Notice that in the above case, the complete device (/dev/sdb) was given to parted and not just one partition. Manual mounting can be as simple as:

mount -t ext4 /dev/sdb1 <dir>

For more information, on Arch Linux, consider reading the man pages of dmesg(1), mkfs(8), mount(8) and parted(8).

How to re-install bootstrap code (GRUB)

2012-04-13T08:01:00.001+04:00

If you have repaired your system from a backup tape (by dump or tar for example), or have installed another OS such as one from Redmond that may have overwritten the master boot record (MBR), you will need to repair the bootstrap area.

Re-install bootstrap code (GRUB)

Please perform the following steps:

Boot from CentOS installation disc (for example, CD #1 or DVD).
For CentOS-4 or CentOS-5 type "linux rescue" at the "boot:" prompt. For CentOS-6 pick "Rescue installed system" from the boot menu.
Mount all filesystems in read-write mode.
Change root to real root ('/') on your hard disk:
```
# chroot /mnt/sysimage
```
Re-install bootstrap code (GRUB).
- If you wish to re-install GRUB to the MBR on a SCSI or SATA disk (/dev/sda):
```
# grub-install /dev/sda
```
- If you wish to re-install GRUB to the PBR of Partition #2 on a SCSI or SATA disk (/dev/sda2):
```
# grub-install /dev/sda2
```
- If you wish to re-install GRUB to the MBR on an IDE disk (/dev/hda):
```
# grub-install /dev/hda
```
- If you wish to re-install GRUB to the MBR on a HP Smart Array disk (/dev/c0d0):
```
# grub-install /dev/cciss/c0d0
```

Resizing Ext3 Partition

2012-04-11T19:09:00.000+04:00

Before changing a file system it should be unmounted, so you'll need to create working standalone boot disks. The CentOS LiveCD would be a good choice. An ext3 filesystem can supposedly be expanded with resize2fs while mounted, but standalone would be safer.
A few ways you can do it:
1. resize2fs
2. parted
3. Partition Magic 7.x
In all cases, first convert ext3 --> ext2: [Note: resize2fs works with ext3.]

tune2fs -O ^has_journal /dev/hdax
e2fsck -v -f /dev/hdax

Resize the partitions with tool of choice.

convert back to ext3
tune2fs -j /dev/hdax
e2fsck -v -f /dev/hdax

Range of IPS on single Ethernet

2012-04-11T18:56:00.003+04:00

How to create a range of ip addresses on ethx. Create a range file in /etc/sysconfig/network-scripts

[root@daddylinux~]# cd /etc/sysconfig/network-scripts

[root@daddylinux~]# nano ifcfg-eth0-range1

Enter this Parameters

DEVICE=eth0
BOOTPROTO=static
HWADDR=00:04:75:D4:C8:F9
IPADDR_START=192.168.0.6
IPADDR_END=192.168.0.10
CLONENUM_START=1
NETMASK=255.255.255.0
ONBOOT=yes
TYPE=Ethernet

CLONENUM_START -- interface clone number to start using for this range. # eg "1"

Which would start at eth0:1

Enable b43 drivers in Backtrack5 r2

2012-04-03T19:14:00.000+04:00

NOTE: Changing additional options in the ncurses config without knowing what the options do might break your kernel!

Enabling b43 drivers in BT5 R2 will require recompiling your kernel.

root@bt:~# apt-get dist-upgrade
root@bt:~# prepare-kernel-sources
root@bt:/usr/src/linux# zcat /proc/config.gz > .config
root@bt:/usr/src/linux# make menuconfig

Configure your kernel to use b43 instead of the default brcmsmac drivers by selecting the BCMA support option. To get to this option, navigate to :

Device Drivers -> Broadcom specific AMBA.

Add the BCMA support as a module, and "Support for BCMA on PCI-host bus" as shown below

Exit the ncurses menu config, and build your kernel package:

root@bt:/usr/src/linux# make prepare
root@bt:/usr/src/linux# make
root@bt:/usr/src/linux# make modules_install
root@bt:/usr/src/linux# make install
root@bt:/usr/src/linux# update-initramfs -u
root@bt:/usr/src/linux# update-grub2

Installing VMware Tools in BackTrack

2012-04-03T18:33:00.000+04:00

NOTE: GNOME VMware image of BackTrack has VMware Tools installed by default.

Backtrack 5 R2

NOTE: KDE Users, please run the following command before installing VMWare tools on BackTrack 5 R2:

root@bt:~# mkdir /etc/cups/ppd

For google's sake, here's the error you get if you do not create that directory, on a BT5R2 KDE install:

Unable to create symlink "/etc/cups/ppd/VMware_Virtual_Printer.ppd" pointing to file "/usr/lib/vmware-tools/configurator/thinprint.ppd".

On an upgraded or freshly installed BackTrack 5 R2:

root@bt:~# prepare-kernel-sources

Next on the VMware Player, we click Virtual Machine -> Install VMware Tools.
Now let's quickly setup the VMware Tools by issuing the following commands:

root@bt:~# mkdir /mnt/cdrom; mount /dev/cdrom  /mnt/cdrom
root@bt:~# cp /mnt/cdrom/VMwareTools-<version>.tar.gz /tmp/
root@bt:~# cd /tmp/
root@bt:~# tar zxpf VMwareTools-<version>.tar.gz 
root@bt:~# cd vmware-tools-distrib/
root@bt:~# ./vmware-install.pl

NOTE: After this a series of questions will come, if you are unsure about them just leave them default. At the time of this posting, the VMWare tools do not compile cleanly with kernel 3.2.6. In particular, the vmxnet driver fails to compile. However, the BackTrack 3.2.6 kernel already has a native vmxnet driver, so there should be no overall loss of performance.

How To Crack WEP Network using Backtrack

2012-04-01T14:28:00.001+04:00

Eventually, you’ll boot into a command line Linux. Type

root@root:~# startx

to load a graphical interface (not needed really, but makes some of us feel more comfortable).

Once you’ve booted into the graphical interface, open a terminal so we can begin. It’s the >_ icon at the top of the screen. Yes, we’re going to use the command line, but don’t worry I’ll be here to hold your hand through the whole process.

Check Your Wireless Card

Start by typing

root@root:~#iwconfig

This will list all the network interfaces on your computer, so we’re looking for either a wlan0, ath0, or wifi0 – which means it’s found a wireless card.

Next, we’ll attempt to put that card into “monitor mode”. This means that instead of trying to join a single network and ignoring everything else not destined for itself, it’s going to instead record everything we tell it to – literally grabbing everything it can possibly see. Type :

root@root:~#airmon-ng start wlan0

If all goes well, you should see something that says: monitor mode enabled on mon0. This means it’s managed to successfully switch your device into monitor mode.

Now, let’s scan the airwaves to figure out some more information about our wifi networks. Type:

root@root:~#airodump-ng mon0

This command is going to give you a screen full of information about every single wireless network and every client connected to them.

Find your Wifi network in the list, and copy the long hexadecimal number from the column labelled BSSID (this is actually the physical MAC address of the router in question). In this case my network is called wep-network, and I can see from the security column that it’s been secured with WEP. The next step is to focus the wifi card to listen only to the packets relating to this network, and lock it to the correct channel (as seen in the CH column) – by default, it’s actually scanning every channel, so you’re only seeing a small percentage of the traffic you want. We can lock it down by first copying the BSSID down, then pressing CTRL-C to end the current command, and typing this:

airodump-ng -c <channel> -w <outputfilename> - -bssid <bssidincluding:'s> mon0

for example, for the network with BSSID of 22:22:22:22:22:22 on channel 11, saving to a file set named “crackme”, I’d type this:

airodump-ng -c 11 -w crackme - -bssid 22:22:22:22:22:22 mon0

When you’ve done this, the same display will appear again, but this time it will actually be recording the data packets to a file, and it’ll be locked into your target network (so you won’t see any unrelated clients).

Two things I want you to take notice of here – first is the bottom half of the screen that shows connected clients. You need to have at least one person connected to the network in order for this to work. Second is the column labelled #Data on the top half. This is how many useful packets of data we’ve captured so far. With any luck, it should be rising – albeit slowly. I’ll tell you now that we need around 5,000 – 25,000 to be able to crack the password. Don’t worry if it’s rising really slowly though, this next command will forcibly inject a bunch of data packets until we have enough.
Open up a new terminal tab by hitting SHIFT-CTRL-T and enter the following command, replacing where appropriate. The client station address is shown on the airodump tab, in the bottom half where it says STATION. Copy and paste it at the appropriate place into the command:

aireplay-ng --arpreplay -b <bssid> -h <client STATION address> mon0

For example

aireplay-ng --arpreplay -b 22:22:22:22:22:22 -h 33:33:33:33:33:33 mon0

After about a minute or so, you should start to see the number of data packets reported in the airodump window rise dramatically, depending on how good your connection to the network is.

Once the number of packets collected has reached about 5,000, we are ready to start cracking those packets. Open up yet another new console window, and type:

aircrack-ng -z -b <bssid> <output filename from earlier>*.cap

The output filename is the one you specified earlier when we narrowed down the airodump utility to a particular network. In my example, I used the name “crackme”. Don’t forget to add a “*.cap” to the end of your chosen filename. In my case, it would be:

aircrack-ng -z -b 22:22:22:22:22:22 crackme*.cap

If you have enough packets, the screen will tell you the key within a few seconds. If not, it will wait until there is another 5,000 packets to work with, then try again. Now you can go make coffee. In my case, it found the password instantly with 35,000 packets – the entire process took about 3 minutes.

If it gives you a password in hexadecimal form, like 34:f2:a3:d4:e4 , then just take the punctuation out and type in the password as a string of numbers and letters, in this case 34f2a3d4e4 . That’s it – that’s how easy it is to hack a WEP-secured network.