My servers are backed up using a little script that works just like Apple's TimeMachine. Every day a backup job moves the latest backup to a folder named by the date of its creation and creates a new backup in the folder latest. Rsync has a nifty feature that creates hardlinks to files in a different folder if the file matches with the current folder. Meaning that you don't create a full backup every time but only sync the differences, i.e. an incremental backup.

All in all that works quite well and I can go back to any date in time to see the state of…