GNU/Linux Desktop Survival Guide
by Graham Williams
Debian From Scratch
The Debian From Scratch CD is an excellent tool for gracefully recovering from serious system problems.
Suppose the root partition of your disk failed and thus you could not reboot your system. Simply boot into the Debian From Scratch live CD and start fixing things up.
To access the USB:
# /etc/init.d/hotplug start
This may give you the opportunity to recover some parts of the hard disk that has failed.