Haven't got a clue - I'm fortunate enough to never ever have to backup Linux :D The only Linux stuff we ever use is appliance based, so doesn't need backing up as it's quicker to just rebuild than restore.
I really do like DPM for backup Microsoft stuff. Been very impressed with it.
This might show my lack of Linux knowledge, but could you do a backup to an MS File Server and then back it up as normal files?
EDITED: 4 Feb 2012 12:34 by PILOTDAN