System Backup with the updates

You can use Remastersys. Please have a look at the following links:

http://www.geekconnection.org/remastersys/
http://www.psychocats.net/ubuntu/remastersys

Hope this helps...

Thanks Emre AYTAÇ , but I am not sure about the Remastersys backup, is it backup all the updates and codecs and the installed softwares. How to use the backed up iso, is it a bootable iso. I have to write it on a dvd then have to boot from that or after installing the system, boot from that backup .iso. The .iso creating process is clear to me,thanks a lot again for helping me . But plz say how to use this.

Remastersys makes an bootable iso of your current system with all of the installed packages, drivers (and also if you want, it backup your home directory like your preferences, your history ...etc). After the operation finishes, burn the iso to a dvd and use it a normal Ubuntu/Kubuntu cd. if you want to test your iso, you can use a virtualization software like Virtualbox, or install to another machine, or boot up and test your live cd. Iso creating process is simple, please have a look at the following link:

http://www.psychocats.net/ubuntu/remastersys

Ps. I didn't personally test it on Kubuntu before, but some people says works on Kubuntu with no problem. They said; "Remastersys repo works, with the ‘karmic’ at the end, try that Joe, tested on Kubuntu 10.10 /32 bit/
Also it’s in Menu, no need to use the CLI syntax"

Ps. There is an iso limit which is 4 GB. If your iso is greater than 4 GB, may be you can remove the contents of apt cache;
sudo apt-get clean

also you can find the largest files or directories.
sudo du -ks / | sort -n -r | head -n 10

and also you can list largest packages in your system (may you want to remove and install later)
dpkg-query --show --showformat='${Package;-50}\t${Installed-Size}\n' | sort -k 2 -n | grep -v deinstall | awk '{printf "%.3f MB \t %s\n", $2/(1024), $1}' | tail -n 10

If the iso not greater than 4 GB, you can burn and use it. But before installing a real system, please test it first, everything is perfect or not. You may try to install it to Virtualbox.

I think Remastersys is the software that you need. Please give it a chance.

Hope these helps...

I want to know another question............if my system get crash then , I have to use the kubuntu dvd first or the backed up dvd. which should use first.

You don't need Kubuntu Dvd, just backup dvd. Because it is a live/install dvd like Kubuntu. But as I said before please test your backup dvd with another machine or Virtualbox to see working properly or not. It is very important. If the installation completed succesfully with your backup dvd, no problem but if any problem occurs, you will backup your system another software.

thank you Emre AYTAÇ , for giving me your time...I do not have any other mechine ...so I want to usevirtualbox. plz help me. I dont know how to use it. Is it a software...?

Virtualbox is a virtualization software like Vmware Workstation. You can use this software for testing operating systems (like Ubuntu, Debian, Gentoo ...etc.) without any partition operation. You can read the details and usage of the software from documentation of Virtualbox website.

http://www.virtualbox.org/manual/UserManual.html

thanks I have installed virtualbox successfully. but how to uninstall the 2nd operating system after testing that.

If the "2nd operating system" is the operating system which installed in Virtualbox, you can remove/delete from the Virtualbox. Please read the user manual.

 from the site
http://www.dedoimedo.com/computers/remastersys.html
I came to know that A typical Ubuntu installation with a footprint of about 3.5GB took about 15 minutes to complete. The final image size was only about 750MB. It means that the iso is lesser size than the system size. actually you said There is an iso limit which is 4 GB. If your iso is greater than 4 GB, may be you can remove the contents. so I am afraid about that. plz elaborate this .

Thanks Emre AYTAÇ, that solved my question.