How to create bootable ISO from an installed OS?

Say I have two systems A and B.

I have installed Ubuntu 12.04 on system A and need same set of settings in system B, for which I am thinking to make a bootable iso from System A(creating as a backup). so that I can make Live USB from the generated iso and boot the System B which will be now the replica of System A.

Could you please tell is there any method or tool in doing this process?

You have many tools that are available for Ubuntu 12.04(some of them are not used anymore for newer versions. but still works for ubuntu 12.04).

• relinux
• remastersys
• Ubuntu Builder
• System Imager

And much more.

I personally advise you to use Relinux.

Download this version from launchpad and not the last version to use the following tutorial on it

Here is a great tutorial how to use.

You can use Clonezilla. It's a great tool if you want all systems have a same copy of OS and softwares. As your requirement look like you want all alike systems. You can clone any hard disk partition or full hard disk using this utility.

You will have a great choice of USB install, network install, samba server, etc. to install your cloned image to other system. Visit this tutorial to learn about "Use Clonezilla Live to clone a computer’s internal hard drive to a USB external drive".

Get Steps here!