rsnapshot is a filesystem snapshot utility based on rsync(1).
rsnapshot makes it easy to make periodic snapshots of local machines,
and remote machines over ssh. The code makes extensive use of hard links
whenever possible, to greatly reduce the disk space required.

It is written entirely in perl with no module dependencies, and has been
tested with versions 5.004 through 5.16.3.

WWW: http://www.rsnapshot.org