i use the tar ball way and it works fine, there are programs out there that do backups, i can't remember the names, either way you have to use a "rescue, or live cd" to restore.
make sure if you use the tar way to exclude the dir's you don't want to backup (like mounts, media, etc..)
Here is the commands i use:
to backup with tar
tar cvpzf backup.tgz --exclude=/backup.tgz --exclude=/proc --exclude=/lost+found --exclude=/mnt --exclude=/media --exclude=/sys --exclude=/home/coredump /
to restore with tar
tar xvpfz backup.tgz -C /