rsnapshot: rsync-Based Filesystem Snapshot Aug 26, 2008, 20 :01 UTC (0 Talkback[s]) (5766 reads) (Other stories by Juliet Kemp)
"That "full backup space" is of course still the gotcha — basically, you'll need a spare disk. However, external disks are increasingly cheap; and rsnapshot can be used remotely with ssh. So you could use one large central disk to keep snapshots of your most important data from multiple clients."
