Introduction: Linux Computer Duplication.

About: Bytesize articles instead of a trilogy in one post.

Here, you will be introduced to ways to duplicate a Debian based Linux computer. You could also use a commercial software program, but we will not be discussing that here. Would probably be easier to use clonezilla live boot cd, but that takes all the fun out of it. This instructable is not intended for beginning users. as I will not be responsible for any issues. Get help from a professional if you are unsure.

Note: What is also nice is that traditional Microsoft based systems such as MSWindows XP and prior can also be cloned or backed up with Clonezilla. The good old Norton ghost open source replacement.

Step 1: Supllemental File Copy.

The point of this exercise is to install just a basic system and then copy a list of installed files from the host machine to the destination system.

Say you want to have several machines to be exactly alike that run Debian or Ubuntu Linux. You will want to set up the first machine the way you want it.

Now we need to get the list of packages that have been installed (software installed via ppa's may still have to be setup manually.)

$ dpkg -–get-selections > installed-software.log

x11-common install
xauth install
xfonts-encodings install
xfonts-utils install
xkb-data install
xml-core install
xz-utils install
zlib1g install

You could probably edit this file to add any last minute packages to be added or removed.

Now you want to do a minimal install of Debian. You will want to uncheck the graphical environment when tasksel asks you what packages you want installed. That will make the rest of the install go quickly.

After the reboot of the finished install, you will want to be able to have ssh and scp file capabilities so on the destination machine so install the ssh programs. (note: on Debian you will also have to install as root sudo and include your user name in /etc/sudoers).

$ sudo apt-get install ssh openssh-server

Now you want to copy the installed-software.log file from the setup machine to the new destination machine via the network.

$ scp installed-software.log [destinationmacineipaddress]:~/.

On the destination machine you need to confirm the repositories are accessible with

$ sudo apt-get update

Now you need to let the destination machine aware of the installed-software.log.

$ dpkg -–set-selections < installed-software.log

And finally you want the system to do the update with the software list.

$ apt-get dselect-upgrade

This will install the duplicate software.

to make sure the machine is update you will want to:

$ sudo apt-get update
$ sudo apt-get upgrade
$ sudo apt-get dist-upgrade

If there are any issues you can always issue the command:

$ sudo apt-get upgrade -f

That should be it for the software install part. if you tweaked any configuration files, those will be needed to be duplicated over to the new machine also.


Step 2:

Just wanted to clone drive to drive locally. Install the destination drive as the second drive (/dev/sdb). Boot with a live linux cd/dvd:

$ sudo fdisk -l

To make sure which drive is which.

$ dd if=/dev/sda of=/dev/sdb

To keep and image for later:

dd if=/dev/hdb | gzip -c > /image.img

Then later to restore the image

gunzip -c /image.img.gz | dd of=/dev/hdb

Just want to clone the system over the network and do not have any fancy cloning software. no problem. Just boot with a live or minimal linux distro and type:

$ sudonc -l -p 9901 | dd of=/dev/sdc

That will start the destination machine listening to receive data. Then boot with a live cd on the destination machine:

$ dd if=/dev/sda | nc ipaddressofhostmachine 9901

i.e. dd if=/dev/sda | nc 9901

Some people might use:

$ sudo nc -p 2222 -l |bzip2 -d | dd of=/dev/sdb

$ sudo bzip2 -c /dev/sda | netcat hostipaddress 2222

i.e. $ sudo bzip2 -c /dev/sda | nc 2222

Step 3: Rsync

rsync -a -e ssh source/

rsync is used to perform the backup operation in UNIX / Linux.

rsync utility is used to synchronize the files and directories from one location to another in an effective way. Backup location could be on local server or on remote server.

Important features of rsync

  • Speed: First time, rsync replicates the whole content between the source and destination directories. Next time, rsync transfers only the changed blocks or bytes to the destination location, which makes the transfer really fast.
  • Security: rsync allows encryption of data using ssh protocol during transfer.
  • Less Bandwidth: rsync uses compression and decompression of data block by block at the sending and receiving end respectively. So the bandwidth used by rsync will be always less compared to other file transfer protocols.
  • Privileges: No special privileges are required to install and execute rsync


$ rsync options source destination

Source and destination could be either local or remote. In case of remote, specify the login name, remote server name and location.

Example 1. Synchronize Two Directories in a Local Server

To sync two directories in a local computer, use the following rsync -zvr command.

$ rsync -zvr /var/opt/installation/inventory/ /root/temp building file list ... done sva.xml svB.xml . sent 26385 bytes received 1098 bytes 54966.00 bytes/sec total size is 44867 speedup is 1.63 $

In the above rsync example:

  • -z is to enable compression
  • -v verbose
  • -r indicates recursive

Now let us see the timestamp on one of the files that was copied from source to destination. As you see below, rsync didn’t preserve timestamps during sync.

$ ls -l /var/opt/installation/inventory/sva.xml /root/temp/sva.xml -r--r--r-- 1 bin bin 949 Jun 18 2009 /var/opt/installation/inventory/sva.xml -r--r--r-- 1 root bin 949 Sep 2 2009 /root/temp/sva.xml

Example 2. Preserve timestamps during Sync using rsync -a

rsync option -a indicates archive mode. -a option does the following,

  • Recursive mode
  • Preserves symbolic links
  • Preserves permissions
  • Preserves timestamp
  • Preserves owner and group

Now, executing the same command provided in example 1 (But with the rsync option -a) as shown below:

$ rsync -azv /var/opt/installation/inventory/ /root/temp/ building file list ... done ./ sva.xml svB.xml . sent 26499 bytes received 1104 bytes 55206.00 bytes/sec total size is 44867 speedup is 1.63 $

As you see below, rsync preserved timestamps during sync.

$ ls -l /var/opt/installation/inventory/sva.xml /root/temp/sva.xml -r--r--r-- 1 root bin 949 Jun 18 2009 /var/opt/installation/inventory/sva.xml -r--r--r-- 1 root bin 949 Jun 18 2009 /root/temp/sva.xml

Example 3. Synchronize Only One File

To copy only one file, specify the file name to rsync command, as shown below.

$ rsync -v /var/lib/rpm/Pubkeys /root/temp/ Pubkeys sent 42 bytes received 12380 bytes 3549.14 bytes/sec total size is 12288 speedup is 0.99

Example 4. Synchronize Files From Local to Remote

rsync allows you to synchronize files/directories between the local and remote system.

$ rsync -avz /root/temp/ thegeekstuff@ Password: building file list ... done ./ rpm/ rpm/Basenames rpm/Conflictname sent 15810261 bytes received 412 bytes 2432411.23 bytes/sec total size is 45305958 speedup is 2.87

While doing synchronization with the remote server, you need to specify username and ip-address of the remote server. You should also specify the destination directory on the remote server. The format is username@machinename:path

As you see above, it asks for password while doing rsync from local to remote server.

Sometimes you don’t want to enter the password while backing up files from local to remote server. For example, If you have a backup shell script, that copies files from local to remote server using rsync, you need the ability to rsync without having to enter the password.

To do that, setup ssh password less login as we explained earlier.

Example 5. Synchronize Files From Remote to Local

When you want to synchronize files from remote to local, specify remote path in source and local path in target as shown below.

$ rsync -avz thegeekstuff@ /root/temp Password: receiving file list ... done rpm/ rpm/Basenames . sent 406 bytes received 15810230 bytes 2432405.54 bytes/sec total size is 45305958 speedup is 2.87

Example 6. Remote shell for Synchronization

rsync allows you to specify the remote shell which you want to use. You can use rsync ssh to enable the secured remote connection.

Use rsync -e ssh to specify which remote shell to use. In this case, rsync will use ssh.

$ rsync -avz -e ssh thegeekstuff@ /root/temp Password: receiving file list ... done rpm/ rpm/Basenames sent 406 bytes received 15810230 bytes 2432405.54 bytes/sec total size is 45305958 speedup is 2.87

Example 7. Do Not Overwrite the Modified Files at the Destination

In a typical sync situation, if a file is modified at the destination, we might not want to overwrite the file with the old file from the source.

Use rsync -u option to do exactly that. (i.e do not overwrite a file at the destination, if it is modified). In the following example, the file called Basenames is already modified at the destination. So, it will not be overwritten with rsync -u.

$ ls -l /root/temp/Basenames total 39088 -rwxr-xr-x 1 root root 4096 Sep 2 11:35 Basenames $ rsync -avzu thegeekstuff@ /root/temp Password: receiving file list ... done rpm/ sent 122 bytes received 505 bytes 114.00 bytes/sec total size is 45305958 speedup is 72258.31 $ ls -lrt total 39088 -rwxr-xr-x 1 root root 4096 Sep 2 11:35 Basenames

Example 8. Synchronize only the Directory Tree Structure (not the files)

Use rsync -d option to synchronize only directory tree from source to the destination. The below example, synchronize only directory tree in recursive manner, not the files in the directories.

$ rsync -v -d thegeekstuff@ . Password: receiving file list ... done logrotate.status CAM/ YaST2/ acpi/ sent 240 bytes received 1830 bytes 318.46 bytes/sec total size is 956 speedup is 0.46

Example 9. View the rsync Progress during Transfer

When you use rsync for backup, you might want to know the progress of the backup. i.e how many files are copies, at what rate it is copying the file, etc.

rsync –progress option displays detailed progress of rsync execution as shown below.

$ rsync -avz --progress thegeekstuff@ /root/temp/ Password: receiving file list ... 19 files to consider ./ Basenames 5357568 100% 14.98MB/s 0:00:00 (xfer#1, to-check=17/19) Conflictname 12288 100% 35.09kB/s 0:00:00 (xfer#2, to-check=16/19) . . . sent 406 bytes received 15810211 bytes 2108082.27 bytes/sec total size is 45305958 speedup is 2.87

You can also use rsnapshot utility (that uses rsync) to backup local linux server, or backup remote linux server.

Example 10. Delete the Files Created at the Target

If a file is not present at the source, but present at the target, you might want to delete the file at the target during rsync.

In that case, use –delete option as shown below. rsync delete option deletes files that are not there in source directory.

# Source and target are in sync. Now creating new file at the target. $ > new-file.txt $ rsync -avz --delete thegeekstuff@ . Password: receiving file list ... done deleting new-file.txt ./ sent 26 bytes received 390 bytes 48.94 bytes/sec total size is 45305958 speedup is 108908.55

Target has the new file called new-file.txt, when synchronize with the source with –delete option, it removed the file new-file.txt

Example 11. Do not Create New File at the Target

If you like, you can update (Sync) only the existing files at the target. In case source has new files, which is not there at the target, you can avoid creating these new files at the target. If you want this feature, use –existing option with rsync command.

First, add a new-file.txt at the source.

[/var/lib/rpm ]$ > new-file.txt

Next, execute the rsync from the target.

$ rsync -avz --existing root@ . root@'s password: receiving file list ... done ./ sent 26 bytes received 419 bytes 46.84 bytes/sec total size is 88551424 speedup is 198991.96

If you see the above output, it didn’t receive the new file new-file.txt

Example 12. View the Changes Between Source and Destination

This option is useful to view the difference in the files or directories between source and destination.

At the source:

$ ls -l /var/lib/rpm -rw-r--r-- 1 root root 5357568 2010-06-24 08:57 Basenames -rw-r--r-- 1 root root 12288 2008-05-28 22:03 Conflictname -rw-r--r-- 1 root root 1179648 2010-06-24 08:57 Dirnames

At the destination:

$ ls -l /root/temp -rw-r--r-- 1 root root 12288 May 28 2008 Conflictname -rw-r--r-- 1 bin bin 1179648 Jun 24 05:27 Dirnames -rw-r--r-- 1 root root 0 Sep 3 06:39 Basenames

In the above example, between the source and destination, there are two differences. First, owner and group of the file Dirname differs. Next, size differs for the file Basenames.

Now let us see how rsync displays this difference. -i option displays the item changes.

$ rsync -avzi thegeekstuff@ /root/temp/ Password: receiving file list ... done > Basenames .f....og. Dirnames sent 48 bytes received 2182544 bytes 291012.27 bytes/sec total size is 45305958 speedup is 20.76

In the output it displays some 9 letters in front of the file name or directory name indicating the changes.

In our example, the letters in front of the Basenames (and Dirnames) says the following:

> specifies that a file is being transferred to the local host. f represents that it is a file. s represents size changes are there. t represents timestamp changes are there. o owner changed g group changed.

Example 13. Include and Exclude Pattern during File Transfer

rsync allows you to give the pattern you want to include and exclude files or directories while doing synchronization.

$ rsync -avz --include 'P*' --exclude '*' thegeekstuff@ /root/temp/ Password: receiving file list ... done ./ Packages Providename Provideversion Pubkeys sent 129 bytes received 10286798 bytes 2285983.78 bytes/sec total size is 32768000 speedup is 3.19

In the above example, it includes only the files or directories starting with ‘P’ (using rsync include) and excludes all other files. (using rsync exclude ‘*’ )

Example 14. Do Not Transfer Large Files

You can tell rsync not to transfer files that are greater than a specific size using rsync –max-size option.

$ rsync -avz --max-size='100K' thegeekstuff@ /root/temp/ Password: receiving file list ... done ./ Conflictname Group Installtid Name Sha1header Sigmd5 Triggername sent 252 bytes received 123081 bytes 18974.31 bytes/sec total size is 45305958 speedup is 367.35

max-size=100K makes rsync to transfer only the files that are less than or equal to 100K. You can indicate M for megabytes and G for gigabytes.

Example 15. Transfer the Whole File

One of the main feature of rsync is that it transfers only the changed block to the destination, instead of sending the whole file.

If network bandwidth is not an issue for you (but CPU is), you can transfer the whole file, using rsync -W option. This will speed-up the rsync process, as it doesn’t have to perform the checksum at the source and destination.

# rsync -avzW thegeekstuff@ /root/temp Password: receiving file list ... done ./ Basenames Conflictname Dirnames Filemd5s Group Installtid Name sent 406 bytes received 15810211 bytes 2874657.64 bytes/sec total size is 45305958 speedup is 2.87

Step 4: Setup Clonezilla on a Webserver.

This is going to be a bit hairy, so I recommend you go to and read about pxe and gpxe before trying this. Now that I know what to do, it is not that bad. What a trip it was getting it to work the first time.

A. You will need to prepare a folder on your web server to hold the files. You will want to set up the rights accordingly. Servername/clonezilladir. We will use the servername/bi for our dir. You will need to change your setup to accommodate your setup. Access to the server must be available for t he client to be imaged. Actually you may need three of them depending on what live zip file(s) you choose.

B. You will need GPXE boot media for your client machine which you can get at One of the reasons I sent you to for learning how to do that. I will not spend time on that except to say you will need to prepare a special script for that. I have an example prepared.  To make a floppy, use the dd command. To make a cd use cdrecord. etc.

C. You will need to go to clonezilla and download the appropriate live image .ZIP at Would not hurt to download all three of them. in the web server directory you set up, unzip the required files (vmlinuz, initrd.img, and filesystem.squashfs in dir live) to server/bi/. You can make it by something like: "unzip -j clonezilla-live-*.zip live/vmlinuz live/initrd.img live/filesystem.squashfs" (Replace clonezilla-live-*.zip with the file name you just downloaded).You will then want to unzip the whole archive with the directories INTACT!

D. You need to get the pxelinux files. (they should be a zip file download here.) Then you need to go into the pxelinux.cfg directory and edit default. Edit your PXElinux config file /pxelinux.cfg/default, and append the following:
label Clonezilla Live
MENU LABEL Clonezilla Live
kernel vmlinuz
append initrd=initrd.img boot=live live-config noswap nolocales edd=on nomodeset ocs_live_run="ocs-live-general" ocs_live_extra_param="" ocs_live_keymap="" ocs_live_batch="no" ocs_lang="" vga=788 nosplash fetch=http://$serverIP/$czdir/five/filesystem.squashfs. See attached sample, but you will need to change it for your setup.

E. Put you boot media in the destination machine and start it up. will have the details how to use clonezilla.

Step 5: Name Change.

Some times you may want to duplicate a server web pages for another server.  But because the web server names are different, all your links are wrong. Your thinking that changing all the web page links will or could be a nightmare since there are at least hundreds of them..

Old link:
a href="http:/oesrvr1"> Click on me to return to the homepage!</a>

New link
a href="http://oemsrvr01"> Click on me to return to the homepage!</a>

Actually it is pretty easy. All you need to do is issue the following command in the affected web directories/

/var/www $ sudo grep -lr -e 'oesrvr1' * | xargs sudo sed -i 's/oesrvr1/oemsrvr01/g'

In a few seconds, you are done.

This command is for a nix based system, but you could share an MSWindows server web directory and let a nix box access the web directories via samba to make the needed changes. (Do it while the server is offline for security purposes.)

Go one step further to automate it using
 sudo grep -lr -e '$1' * | xargs sudo sed -i 's/$1/$2/g'

Then at the command line you could use:
$ oesrvr1 oemsrvr01