"The only way of restoring a backup is to deploy that backup as a new server." Not true. You can restore a backup to a node as long as it has enough unallocate

"The only way of restoring a backup is to deploy that backup as a new server." Not true. You can restore a backup to a node as long as it has enough unallocated disk space. The simplest ways to create enough unallocated disk space are to create a new node or to delete or resize all your disk images.