Backups
If you need to restore a backup, look at how backups are done on each VPS (script /usr/local/sbin/gigatux-backup.sh) and use the rdiff-backup --restore functionality to restore to an appropriate location. If a full VPS restore is required, create a new logical volume to do this (lvcreate) and change the relevant /etc/xen/xenXX file to point to this to test it out.