Download it here. | The original article was published here.

This is my init.d script for automatic startup and shutdown of chiliproject (mongrel) using RVM and REE env during system bootup. You can use/modify this script to suite your need for your chiliproject/redmine installation.

#!/usr/bin/env bash
#
# Chilliproject init script written by Animesh Das <jobs4ani at gmail dot com>
#
# chkconfig: – 16 84
# description: Init Script for Chiliproject
#
# processname: mongrel

# source function library
. /etc/rc.d/init.d/functions

# Get network config
. /etc/sysconfig/network

[ "${NETWORKING}" = "no" ] && exit 0

# App Settings
APP_USER=chili
APP_USER_HOME=/home/$APP_USER
APP_NAME=Chiliproject
APP_ROOT=$APP_USER_HOME/chiliproject
APP_PIDFILE=$APP_ROOT/log/chiliproject.pid

# Daemon Settings
DAEMON_USER=$APP_USER
DAEMON_GROUP=$APP_USER
DAEMON_NAME=mongrel
DAEMON_CMD=mongrel_rails
DAEMON_ENV=production
DAEMON_HOME=$APP_ROOT
DAEMON_LOGFILE=$DAEMON_HOME/log/$DAEMON_NAME.log
DAEMON_PIDFILE=$DAEMON_HOME/log/$DAEMON_NAME.pid
DAEMON_LOCKFILE=$DAEMON_HOME/tmp/$DAEMON_NAME.lock
DAEMON_ARGS=”-e $DAEMON_ENV -d -p 9090 -l $DAEMON_LOGFILE -P $DAEMON_PIDFILE -c $DAEMON_HOME –user $DAEMON_USER –group $DAEMON_GROUP”

# Set the environment
source $APP_USER_HOME/.rvmrc && [[ -s $APP_USER_HOME/.rvm/scripts/rvm ]] && source $APP_USER_HOME/.rvm/scripts/rvm
if [[ -s "$APP_USER_HOME/.rvm/environments/ree-1.8.7-2011.03" ]]
then
source “$APP_USER_HOME/.rvm/environments/ree-1.8.7-2011.03″
#exec mongrel_rails “$@”
else
echo “ERROR: Missing RVM environment file: ‘$APP_USER_HOME/.rvm/environments/ree-1.8.7-2011.03′” >&2
exit 1
fi

# Ruby config
MONGREL_BIN=$(type -P $DAEMON_CMD)

start() {
echo -n $”Starting ${APP_NAME}: “

cd $DAEMON_HOME
cat /dev/null > $DAEMON_LOGFILE
sleep 2
daemon $MONGREL_BIN start $DAEMON_ARGS
sleep 2
RETVAL=$?
if [ $RETVAL -eq 0 ]; then
touch $DAEMON_LOCKFILE
fi
echo
}

stop() {
echo -n $”Stopping ${APP_NAME}: “
sleep 2
cd $DAEMON_HOME
killproc -p $DAEMON_PIDFILE
RETVAL=$?
[ $RETVAL -eq 0 ] && /bin/rm -f $DAEMON_LOCKFILE $DAEMON_PIDFILE
echo
}

case “$1″ in
start)
start
;;
stop)
stop
;;
restart)
stop
start
sleep 3
;;
status)
status -p $DAEMON_PIDFILE $DAEMON_NAME
;;

*)
echo “Usage: $SCRIPTNAME {start|stop|restart|status}” >&2
exit 3
;;
esac

1.0 Introduction

In this Hands-on Labs session, we’re going to use the Linux Ubuntu 10.04 LTS (Lucid Lynx) release. Ubuntu 10.04, Lucid Lynx, is the platform of choice for anybody who intends to build and deploy large-scale infrastructure, whether you’re trying to build the next Facebook, or the next Google, or the next eBay. If you want to start on [Amazon's cloud-platform] EC2 and migrate to your own managed private cloud, Ubuntu 10.04 is going to be the platform for you. Lucid Lynx will be the third long-term support (LTS) release by Ubuntu. LTS releases arrive bi-annually and are supported for three years on desktops and five years for servers.

Ubuntu 10.04 LTS Server Edition: Lean, fast and powerful – Ubuntu Server delivers services reliably, predictably and economically – and easily integrates with your existing infrastructure.
Ubuntu is an operating system built by a worldwide team of expert developers. It contains all the applications you need: a web browser, office suite, media apps, instant messaging and much more. Ubuntu is an open-source alternative to Windows and Office.

Ubuntu Enterprise Cloud (UEC): The UEC allows you to build your own private cloud. The Ubuntu Cloud Planet is a window into the world, work and lives of those that work on making Ubuntu the best cloud platform there is. With Ubuntu Enterprise Cloud you can bring the same self-service capability into your data center using the same tools and APIs used on Amazon EC2.

With Ubuntu, you can build the perfect cloud environment for your business whether private, with Ubuntu Enterprise Cloud (UEC), or public, with Ubuntu Server on Amazon EC2. Because UEC uses the same machine images as Amazon EC2, you can create a hybrid cloud or migrate between public and private easily at any time.

Private clouds offer immediacy and elasticity in your own IT infrastructure. Using Ubuntu Enterprise Cloud, you can experience the benefits of cloud computing behind your firewall. Deploy workloads and have them running immediately. Grow or shrink computing capacity to meet the needs of your application.

Solution:

In this Hands-on Lab session, you’ll learn how to setup virtual network on VMware (you may also use any other virtual machines like MS VirtualPC, Linux Xen, or VirtualBox from Sun). In this lab session, you’ll learn to Build your Own Private Cloud using Ubuntu 10.04 Eucalyptus Enterprise Cloud Computing Platform.

Part 1: Install & Configure Ubuntu 10.04 Enterprise Cloud Server

Step 1: Getting Started & Hardware Pre-requisites
In this Hands-on Labs, it’s assumed that your target computer is connected to the internet. After installing the cluster controller, log into your machine and ensure you perform software updates to bring your systems up-to-date. In the second part, you will install the node controller. For minimum hardware requirements check here.

Step 2: Install Ubuntu 10.04 LTS Enterprise Cloud

Hope over to http://www.ubuntu.com/getubuntu/download-server website and download the Linux Ubuntu 10.04 64-bit ISO which at the time of writing this lab manual was “Ubuntu-10.04-server-amd64.iso“

• Once you have downloaded the Ubuntu ISO specific to your distribution, you have the option burning it into CD or just by using the ISO package to install it from your virtual machine, in our case VMware.
• Fire-up a new virtual machine and perform the initial configuration and setup to use ISO package.
• Start the virtual machine, and you should be able to see the first Ubuntu installation screen.
• From Fig. 1, select the language desired and hit Enter key.
• From Fig. 2, select the option desired and then hit the Enter key to commence installation. In our case we have selected to Install Ubuntu Enterprise Cloud option.

I am a working professional. So I have to spent most of my time, in office, works, R&D, and learning new technologies. Infact I do not find enough time to spend with my family, specially my one year old daughter. So you can understand how severe time constraint I am in, specially spending time in writing such big blog post. So, unless it helps others, there is no point of composing, formatting such big article which will take hours.

Now do you really want me to post this complete article? If yes, post your comments and let me know why you want this article to be posted and how it can help you. I promise I will post rest of the content.

Thank you so much to all who have find this post useful and forced me to update it with rest of the content. Thanks again for your response. Please accept my apology for my late and delayed resposne. Now as I’ve mentioned above, I was extremely busy and due to lack of time it is difficult to post such a huge content. Anyway without wasting any further time here goes the rest of this content…..

7. From Fig. 3, Choose language screen, select English option, and hit the Enter key.

Fig. 3

8. From Fig. 4, Choose language screen, Choose a country, select United States option, and hit Enter

Fig. 4

9. From the Ubuntu installer main menu screen, Fig. 5, accept the default selected <No> and hit the

Enter key to continue.

Fig. 5

10. From the Ubuntu installer main menu screen, Fig. 6, Origin of keyboard, select USA and hit the Enter key to continue.

Fig. 6

11. From the Ubuntu installer main menu screen, Fig. 7, Keyboard layout, select USA and hit the

Enter key to continue.

Fig. 7

12. From Fig. 8, the Detecting hardware to find CD-ROM drives screen, wait for the system complete the process.

Fig. 8: System Detecting hardware to find CD-ROM drives

13. From Fig. 9, the Loading additional components screen, wait for the system complete the process.

Fig. 9: System Loading additional components

14. From Fig. 10, the Configure the network screen, enter desired the Hostname: “cloudoscarcloud.com”, change as desired, and hit the Tab key to select <Continue> and hit the Enter key to continue.

Fig. 10

15. From Fig. 11, the Select cloud installation mode screen, leave the cloud control address blank, hit the Tab key to select <Continue> and hit the Enter key to continue.

Fig. 11

16. From Fig. 12, the Select cloud installation mode screen, accept the selected default option, hit the

Tab key to select <Continue> and hit the Enter key to continue.

Fig. 12

17. From Fig. 13, the setting up the clock screen, wait for the system to complete the process.

Fig. 13

18. From Fig. 14, the Configure the clock screen, accept the default selection for the time zone, or change as desired, and then hit the Enter key to continue.

Fig. 14

19. From Fig. 15, the Starting up the partitioner screen, wait for the system to complete the process.

Fig. 15

20. From Fig. 16, the Partition disks screen, accept the default selection, or change as desired, and then hit the Enter key to continue.

Fig. 16

21. From Fig. 17, the Partition disks screen, accept the default selection, or change as desired, and then hit the Enter key to continue.

Fig. 17

22. From Fig. 18, the Partition disks screen, select <Yes>, or change as desired, and then hit the Enter

key to continue.

Fig. 18

23. From Fig. 19, the Partition disks screen, accept the default selection of 21.2GB, or change as desired, and then hit the Tab key to select <Continue> and hit the Enter key to continue.

Fig. 19

24. From Fig. 20, the Partition disks screen, read the warning and then select <Yes>, or change as desired, and then hit the Enter key to continue.

Fig. 20

25. From Fig. 21, the Partition disks screen, wait for the system to complete the process.

Fig. 21

26. From Fig. 22, the Installing the base system screen, wait for the system to complete the process.

Fig. 22

27. From Fig. 23, the Setup users and passwords screen, enter the full name of the user: “Cloud

Admin”, or change as desired, and then select <Continue> and hit the Enter key to continue.

Fig. 23

28. From Fig. 24, the Setup users and passwords screen, enter the username of the user: “cadmin”, or change as desired, and then select <Continue> and hit the Enter key to continue.

Fig. 24

29. From Fig. 25a, the Setup users and passwords screen; enter the password of the user “cadmin”, and then select <Continue> and hit the Enter key to continue.

Fig. 25a Note: Reenter the password when prompted.

30. From Fig. 25b, the Setup users and passwords screen; accepted the selection <No> not to encrypt your home directory, or change as desired, and then hit the Enter key to continue.

Fig. 25b

31. From Fig. 26, the Configuring apt screen, wait for the system to complete the process.

Fig. 26

32. From Fig. 27, the Configuring the package manager screen; leave HTTP proxy blank, hit the Tab

key to select <Continue> and hit the Enter key to continue.

Fig. 27

33. From Fig. 28, the Configuring apt screen, the system will continue with configuring apt, wait for the system to complete the process.

Fig. 28

34. From Fig. 29, the Select and install software screen, select the desired update option, and hit the

Enter key to continue.

Fig. 29

35. From Fig. 30, the Select and install software screen, wait for the system to complete the process.

Fig. 30

36. From Fig. 31, the Postfix Configuration screen; under System mail name: “cloud.oscarcloud.com”, or change as desired, and then hit the Tab key to select <Continue> and hit the Enter key to continue.

Fig. 31

37. From Fig. 32, the Configuration eucalyptus-cc screen; accept the default Eucalyptus cluster name: “cluster1″, change as desired, and then hit the Enter key to continue.

Fig. 32

38. From Fig. 33, the Configuration eucalyptus-cc screen; leave the IP address range, enter:

“192.168.83.30-192.168.83.50″, or change as desired, and then hit the Tab key to select

<Continue> and hit the Enter key to continue.

Fig. 33

39. From Fig. 34, the Select and install software screen, the system will continue with the installation process, wait for the system to complete the process.

Fig. 34

40. From Fig. 35, the Installing GRUB boot loader screen, wait for the system to complete the process.

Fig. 35

41. From Fig. 36, the Installing GRUB boot loader screen, accept the default selection to install GRUB

boot loader, or change as desired, and hit the Enter key to continue.

Fig. 36

42. From Fig. 37, the Finishing the installation screen, wait for the system to complete the process.

Fig. 37

43. From Fig. 38, the Finish installation screen; Installation complete. Remove the installation

CD, and hit the Enter key to restart the system.

Fig. 38

44. From Fig. 39, you can observer the system startup process.

Fig. 39: Ubuntu cloud server startup process.

45. From Fig. 40, enter your username and password, same as the one entered during the installation stage, and hit enter.

Fig. 40: Ubuntu cloud server with successful login.

46. To check you server IP address, if the Ifconfig command, as shown in Fig. 41.

Fig. 41: Checking server IP address

47. We’re done with this section.

Step 3: Update Ubuntu 10.04 Operating Systems

It is useful to update your system with the latest components and system patches. The first command below asks Ubuntu to update its database of available packages, and the second command installs the latest packages based on your current configuration. We run the upgrade command twice to ensure that any packages that may have post-upgrade dependencies also have an opportunity to be upgraded.

1. From the command line, enter the following commands, one at a time.

$ sudo apt-get update

$ sudo apt-get -u upgrade

Note 1: The sudo command is used to run privileged operations on the Ubuntu platform. The first time you run the command, it will ask for your password. Subsequently, it will not ask for your password again for a short period of time (typically 15 minutes).

Note 2: apt-get is the program Ubuntu uses for managing the system’s packages. When used to manipulate the core packages of the operating system, it needs to be run in conjunction with the sudo command.

2. We’re done with this section

3. You’re now ready to begin any other application installation as desired!

Part 2: Ubuntu Linux Node Installation

Node installation under the Ubuntu 10.04 install is as straight forward as the Cloud controller.

1. At the start of the node installation, the option “Install Ubuntu Enterprise Cloud” should be selected just like the Cloud controller installation. However, in the Select Cloud Installation Mode screen (Fig.

42), select “Node controller” as the install method.

Fig. 42: Cloud installation mode.

Note 1: Node’s hostname use: “node01.oscarcloud.com”, you may change as desired, see Fig.

43.

Fig. 43

Note 2: The rest of the installation remains the same as installing the Cluster controller in Part 1.

2. When done with installation and rebooted the node back, use Ifconfig command to check network devices installed on the node controller, as shown in Fig. 44.

Fig. 44

3. Next, use the ping command to test that you can connect to the Cloud controller, as show in Fig. 45.

Fig. 45

4. We’re done with this section.

Part 3: Cloud provisioning from Ubuntu

Step 1: Logging into Ubuntu Cloud Admin console

In this section, I will show you how install the node controller. Once the Cluster controller and nodes are installed the cloud is managed via the cluster controller’s IP address. The system can be managed via the

Web interface by connecting on port 8443. For example, assuming the cluster controller’s IP address is

192.168.83.236, the URL http://192.168.83.236:8443 can be used to manage the cluster.

1. To access the Ubuntu Cloud Admin console, fire-up another virtual machine, in our case it’s WinXP PC, and then use your favorite browser and enter the URL: http://192.168.83.236:8443. You will be prompted for Security Alert window as shown in Fig.46. Click Yes to accept the security certificate.

Fig. 46

2. The Web login will be shown at this point as shown in Fig. 47. The default username “admin” with the password “admin” can be used for the initial login.

Fig. 47: Enterprise cloud login.

3. Once you are logged in, Eucalyptus will prompt you for the administrator’s new password as well as email address and the cluster host IP address, as shown in Fig. 48. Change as desired and then click the Submit button to update the changes. (Note: we have changed to Firefox browser)

Fig. 48: First time configuration for Ubuntu Enterprise Cloud.

4. When you hit the Submit button, from Fig. 48 above, you’ll be brought to the screen shown in Fig. 49.

Notice at the moment there is only one user, who is the server administrator.

Fig. 49: Ubuntu Enterprise Cloud admin console

5. Before we do anything, we need to register Walrus, this can be found on the Configuration tab. Enter under Walrus host: 192.168.83.236, which is the IP of the cloud controller, then click the Register Walrus button.

Fig. 50

Note: The integration of UEC goes beyond the installation. The Eucalyptus Web interface supports the concept of a Store, and Extras. The Store and Extras provide similar function. They are repositories and links to the Internet for operating systems supported within the cloud. The Images tab

is initially empty, as shown in Fig. 51.

Fig. 51: Ubuntu Enterprise Cloud admin console – Images tab

Step 2: A closer look at Ubuntu enterprise cloud

The Web-based management console is made up of seven tabs: Credentials, Images, Store, Users, Configuration, Services, and Extras. The major advantage of the console over the command line is that it gives a large view of the whole environment in one location, as shown in Fig. 51.

• Credential tab: The Credentials pane contains two fundamental configuration parameters: the admin account information, and the credentials information. The admin account information is the basic authentication and authorization information needed to access the Web interface; whereas the credential information is the authentication (keys) needed to access cloud infrastructure such as private cloud resources managed by the enterprise or public ones such as Amazon’s cloud computing services.

• Images tab: - Virtual machines within Eucalyptus are made up of images, and these “base” images are made up of three discrete pieces: a kernel, a ram disk, and an OS image. These images are stored under the Images tab. This images tab integrates tightly with the Store tab which provides administrators a set of four Images available for download and quick provisioning, see Fig. 52.

• Users tab: - Eucalyptus also supports additional users, which are provisioned under the Users tab.

• Configuration tab: – The Configuration tab is the major tab and is used to provision the settings for the cloud, including its IP, DNS, storage, and cluster information. This is really for changing the parameters, as the Ubuntu integrated install process provisions most of these out of the box.

• Services tab: -The Services tab is a bit misleading. It is not to start and stop services, but rather a

‘help” tab. It provides links to documentation, training, and community Web sites.

Fig. 52: Store tab in Enterprise Cloud console showing images that are ready for installing.

• Extras tab: - Finally, the Extras tab contains other Linux versions as well as older Ubuntu images that will also function with the platform. The Extra tabs, also contains client tools, see Fig. 53.

Fig. 53: Extras tab in Enterprise Cloud console showing Eucalyptus-certified Images that are ready for installing.

Note: if you scroll down you’ll also see the Eucalyptus-compatible Tools which you can also install, see Fig. 54.

Fig. 54

Step 3: Set up your cloud

In this section I’ll show you how to download and install tools necessary to help you manage your cloud.

1. Download and install a tool to allow you to start and stop instances, see Fig. 54 located in the Extras tab. You can use either Elastic Fox or Euca2ools for free. Euca2ools is open source and comes with Ubuntu Server

2. Click euca2ools link from Fig. 54 to install it access the package and the guide on how to install it.

Step 4: Install an image from the store

The following is by far the simplest way to install an image. However, advanced users may be interested in learning how to Bundle their own image.

1. The simplest way to add an image to UEC is to install it from the Image Store on the UEC web interface from the Store tab, see Fig.52 above.

2. From the available images under All Images heading, locate the desired image and then click on the Install button to install it the desired image, in our case: Ubuntu 9.10 – Karmic Koala (amd64), see Fig. 55.

Fig. 55: From the UEC Store tab, click Install button to install Ubuntu 9.10 –Karmic Koala (amd64)

Note: It will take several minutes to download & complete installation, so take time-off for some coffee.

3. Once the image has been downloaded and installed, you can click on “How to run?” that will be displayed below the image button to view the command to execute to instantiate (start) this image.

The image will also appear on the list given on the Image tab, see Fig. 56.

Fig. 56: Click the ”How to run?” link.

Note: When you click “How to run?”, a window will open as shown in Fig. 57. Click the Close

button when done.

Fig. 57: Information on how to run: Ubuntu 9.10 –Karmic Koala (amd64)

4. Now if you click the Image tab, should notice that we have some images, as shown in Fig. 58.

Fig. 58: Image tab, now showing some images.

5. We’re done with this section.

6. Take your time to some Google search to help you learn how to extend the knowledge that you have learned in this lab session.

Note: Shutdown the systems in this order: first the node controller followed by the cloud controller. Use the following command to shutdown: “sudo shutdown now -h”.

To power up the cloud system, fire-up the cloud controller first followed by the node controller.

Step 5; Summary

The Ubuntu integrated install of Eucalyptus and the Web-based enterprise console is a welcome addition to cloud computing. It makes a consistent and quick deployment of the technology much more attainable by many enterprise shops.

09-Feb-2012, UPDATED: Those who are interested to read this article/manual offline, can download it in PDF format from this link.

References

1. Installing Ubuntu 9_10 and the Eucalyptus enterprise cloud computing platform http://www.canonical.com/projects/landscape/cloud-management

2. Landscape Cloud Management Canonical https://help.ubuntu.com/community/UEC/CDInstall

3. Private cloud Ubuntu – http://www.ubuntu.com/cloud/private-steps

The centre was established as part of the 2004 Malaysian Public Sector OSS Master Plan, to guide and co-ordinate the implementation of OSS in the public sector.

The latest OSS adoption figures, released on 24 July, show that 521 of the country’s 724 public sector agencies (72 per cent) have adopted OSS. This is a significant increase from 354 agencies (49 percent) in 2008 and 163 (22.5 per cent) in 2007.

Malaysia is certainly raising the bar in terms of open source adoption and leadership!

1. Let’s say our corrupted filesystem is at partition /dev/sdb3 of ext3 type. We will mount the partition under /mnt/sdb3, so create the directory structure if you dont have it already.

    

   Also, create the following directory structure to keep backup data.

   mkdir /sdb3-backup
   mkdir /sdb3-backup/image
   mkdir /sdb3-backup/copy

   Note that ext3 filesystem is same as ext2, with only addition of journal. So our entire technique will use ext2 filesystem if even our corrupted filesystem is ext3 type. Because our aim is to recover data not journal recovery (which is unrecoverable as far as I know). So be carefull while you issue any of my commands, unless explicitly told dont add any ext3 filesystem type in any of our command. Use all my command as it is written below.

2. Before applying this technique be sure that your superblock is corrupt only not the entire disk or something else.

   USE THE INSTRUCTION BELOW TO CHECK IT

    

   A. Try to mount the disk read only using

   mount -t ext2 /dev/sdb3 /mnt/sdb3 -o ro

   OR

   mount -t ext2 -o ro,errors=recover,
   errors=<span class="kwrd">continue</span> /dev/sdb3 /mnt/sdb3

3. Check the message you are getting. it must be something like below :

   mount: wrong fs type, bad option,
   bad superblock on /dev/sdb3,
   or too many mounted file systems

   B. Now try “dmesg | more” to actually verify if the superblock is really damaged. We will see a line like below :

    

   EXT2-fs: unable to read superblock

   Now we will first start to recover the data by mounting it then we will try to correct the file system.

    

4. Before you proceed further, I’d recommend taking an image, by executing :

    

   dd <span class="kwrd">if</span>=/dev/sdb3 of=/sdb3-backup/image/backup

   and then using the loop device to work on that. If the partition is bigger than 2 gig you will probably need to compress it alternatively by executing

   dd <span class="kwrd">if</span>=/dev/sdb3 | gzip > /sdb3-backup/image/backup.gz

   Note: If compressing the loop device doesn’t work and you have to work on the bare hardware and using an alternate superblock failed too, a last dirty fix could be

    

   mke2fs -S /sdb3-backup/image/backup

   Or if the dd result is too big use

    

   mke2fs -S /dev/sdb3

   This will rewrite the superblocks, you will then need to run e2fsck to clean up. This did the trick for me on a drive that got a whole bunch of bad sectors that I had to get data off.

   Hmm, if I’d only have another HDD to save the data, I’m would be happy ; to do

   dd <span class="kwrd">if</span>=/dev/hda2 of=/dev/xyz
   e2fsck -b 32768 /dev/xyz

   e2fsck restored the first superblock and my problems are gone…but unfortunately I do not have another HDD which can hold this big chunk of data

5. Linux file system writes backup of superblock in different locations. Find the backup superblocks using

   mke2fs -n /dev/sdb3

   The above command will give you a result like below

   mke2fs 1.35 (28-Feb-2004)
   Filesystem label=OS type: LinuxBlock size=4096 (log=2)
   Fragment size=4096 (log=2)14385152 inodes, 28754341
   blocks1437717 blocks (5.00%) reserved <span class="kwrd">for</span> the
   super userFirst data block=0878 block groups32768
   blocks per group, 32768 fragments per group16384
   inodes per groupSuperblock backups stored on
   blocks:32768, 98304, 163840, 229376, 294912, 819200,
   884736, 1605632, 2654208,4096000, 7962624, 11239424,
   20480000, 23887872

    

6. Now please note the superblock backup blocks number at the last line and the block size(which is multiple of 1K=1024b). In our case the block size is 4096 that mean 4K (4096/1024=4)

   While the block number which must be given to mount is based on the blocksize which is installed on the hard disk (4k in my case), the block number which must be given to mount is calculated on a 1k-block-basis, so I had to multiply 32768*4.

   Now we will try to mount the corrupted filesystem partition. We have to tell mount command to use backup superblocks so we will calculate the first backup superblock (if it is OK) 32768*4 = 131072. Now mount with the command below :

   mount -t ext2 -o sb=131072 /dev/sdb3 /mnt/sdb3

   Now imagine the backup at position 32768 was damaged too . . . then you just try again with the backup stored at position 98304, and 163840, and 229376 etc. etc. until you find an undamaged backup ( there are several backups so if at least one of those five is okay. BINGO! )

   Use the formula below to calculate the backup superblock location :

   Superblock backups stored on blocks location
   * Block size <span class="kwrd">in</span> K(i.e.Block size/1024) =
   Nmount -t ext2 -o sb=N /dev/sdb3 /mnt/sdb3
   (replace N with the result of the calculation)

7. If you successfully able to mount the partition, go to the mounted partion and copy data using

   cd /mnt/sdb3
   cp -R /mnt/sdb3/data /sdb3-backup/copy/.

   If any of the above steps fails. You need to consult a experienced data recovery experts.

   In 90% case of damaged superblock this technique of data recovery works. Hope the above technique will help you too. Please post your result if you use the technique in this article.

   And at last I would like to say “ALWAYS BACKUP YOUR DATA IN MULTIPLE / DISK OR MEDIA” so if one fails you can restore from others.

Derived from my original article publish in My TechBlog

That’s because open source software and the methodologies that accompany it have already been proven to be the chosen route for the vast majority of companies aiming to capitalise on the cloud phenomenon.

For evidence of this, you need look no further than the route companies such as Amazon, Google and Rackspace have taken in building out the massive datacentres they plan to begin selling capacity on in the coming years.

Without fail in each of these examples, open source is either at the core or forms a vital component of what’s on offer. And as cloud computing becomes more a prominent topic, so open source will find greater traction in the market.

The reasons open source is a popular route are not difficult to find. Since the cloud computing players are extremely technically proficient, they have sufficient skill in-house to capitalise on the more open nature of open source – and in doing so, can build a far lower cost solution than what would be on offer from a proprietary technology.

These solutions’ open nature furthermore allow cloud providers to mould and form tools to their own needs, changing and adapting underlying technology rapidly so that extra performance can be eked out of a solution.

Incidentally, cloud companies using open source technologies gain the useful side-effect of adhering to the open standards that the majority of open source solutions subscribe to. This proves to be a great benefit down the line when it comes to integrating disparate line of business systems or solutions providing specific functionality to a business silo.

A number of companies are wondering when exactly cloud computing will hit South Africa, since the topic is becoming an important part of the planning most enterprises in the more developed US or European markets are doing today.

Because of the bandwidth limitations we face locally and despite the arrival of new undersea cables, cloud computing will take on a different form in South Africa to markets where bandwidth is ubiquitously available.

My personal belief is that South African companies will become involved with cloud computing from an internal perspective, building clouds that exist inside their datacentres, but function similarly to clouds located at service providers’ offsite datacentres.

It stands to reason that these customers will need to look at open source technologies just like their outsourced peers, since the level of scalability, customisability and control is just not there in the proprietary world.

For that reason I can’t see why open source won’t go from strength to strength locally over the coming years.

The exploit by Anil Kurmus is significant because it successfully targeted the so-called SSL renegotiation bug to steal Twitter login credentials that passed through encrypted data streams. When the flaw surfaced last week, many researchers dismissed it as an esoteric curiosity with little practical effect.

For one thing, the critics said, the protocol bug was hard to exploit. And for another, they said, even when it could be targeted, it achieved extremely limited results. The skepticism was understandable: While attackers could inject a small amount of text at the beginning of an authenticated SSL session, they were unable to read encrypted data that flowed between the two parties.

Read more