Thought I’d go ahead and post this one because I quite regularly see in linux forum’s people asking “what is the best way to backup my whole system”. Well, as long as you have enough hard drive space to do so, I would recommend a simple tarball:
tar cvjpf /$BACKUP_LOCATION/system-backup-$DATASTAMP.tar.bz2 / \ --exclude=/proc/* \ --exclude=/sys/* \ --exclude=/tmp/* \ --exclude=/mnt/* \ --exclude=/home/*
I will generally build this archive every month or so because the system configuration doesn’t change very often, however I will separately backup the home directories every week. Unfortunately this method is cumbersome if you don’t have the hard drive space, where partimage may be a better option for others (which simply makes an image of your partition and can be broken into cd or dvd sizes). Either way, the tarball method is my favorite, especially if you can get the ball onto a dvd+-rw. Especially since the only steps required to do a system restore is a quick live cd, untar into your new root, install grub, and your done.
Note: You do need to make sure all of your partitions that you want backed up are mounted (this notice is aimed more for gentoo users, where boot is NOT mounted by default).