Command line tools for making snapshot of ubuntu

Command line tools for making snapshot of ubuntu

After uninstall zeitgiest tools using sudo apt-get purge
libzeitgeist-1.0-1 python-zeitgeist zeitgeist-core command, I could not
login to my account with GUI: Not able to login after rebooting.
In this case, how could I make snapshot or backup image so that I can
recover using command line? I mean, when similar issue occurs, I need to
login CLI with Ctrl-Alt-F3 key, then I can recover using the command line
backup tool.
I use ubuntu 12.04.