Recently I had the need to re-image some machines a few times in just a period of a week.
When re-imaging just one machine the process of installing the OS, all the updates and extra software is not that bad.
However, when that becomes a routine it can take up some time.

For most of the time I’m having to deal only with Ubuntu, so to solve that problem I installed the OS and all the updates available and also a few extra software packages that I normally use from the get go to create a baseline installation.

So whenever the need arises to re-image a machine or install a fresh copy of Ubuntu, instead of going through the same tedious process all over again, all it takes is to plug-in the pre-built disc image containing the baseline installation of the OS

The steps to create an ISO of the OS to be used as a distro or simple as a backup can be done through the software Remastersys.
In their website they have a short guide explaining the process:

The Synaptic Method:

  1. In Firefox, go to :

http://www.remastersys.com/ubuntu/remastersys.gpg.key

save file as text someplace where you can find it.

  1. In synaptic, go to Settings/Repositories; select “Authentication” tab and “Import Key File” just downloaded.

  2. Still in synaptic, go to “Other Software” tab and click “Add”, then enter the apt line and replace oneiric with either lucid, maverick, or natty to match your Ubuntu version:

    deb http://www.remastersys.com/ubuntu precise main

    or if you are using quantal

    deb http://www.remastersys.com/ubuntu quantal main

  3. Leave the repositories tab and “Reload”.

  4. Search for “remastersys” and select the packages you want to install. Edit/Apply Marked Changes.

The Manual Method

As root – issue ‘sudo su’ in the terminal window prior to the following command.

Download and apply the repository gpg key.

sudo su
wget -O – http://www.remastersys.com/ubuntu/remastersys.gpg.key | apt-key add –

Add the following line that corresponds to your version of Ubuntu to your /etc/apt/sources.list

Remastersys Precise

deb http://www.remastersys.com/ubuntu precise main

Remastersys Quantal

deb http://www.remastersys.com/ubuntu quantal main

Now just apt-get update or reload in Synaptic to have the new Remastersys signed repository ready to use!

The main package you will need to install at the very least is “remastersys”. This is the base package with the cli version of remastersys.

If you want the official remastersys gui, install “remastersys-gui” as well which will provide you with a gui that has more features and a menu item for it.

There is also an alternate gui written in python called “remastersys-gtk” that is available.

Both will provide you with a gui that makes it much easier to use remastersys.

Links:
Link of the tutorial above
Creating custom distros with Remastersys