Rescue CD useage

When you insert the CD, choose advanced options and then rescue. At one point it will ask where to try to start a shell. If the system is fully LVM'd, then use

/dev/mapper/volumegroupname-root

and start the shell there. If it can't, then it will give a warning and make mounts on /target/mount

when you get in mount -a but check the directory listing of the mounts. It may be necessary to unmount everything and remount it by hand.

If everything is mounted in /target/ then cd to target and

chroot .

NB make sure you mount the proc filesystem with

mount -t proc proc /target/proc -o defaults remount

you can then run apt-get grub or lilo from there