XFS

• https://wiki.archlinux.org/index.php/XFS

15:07 < xxxxx> absolutely positootly requires a 64bit kernel.  supported in 
                rhel6 and many other current distros.   requires a LOT of ram 
                to safely fsck a large volume in case of a crash.
15:07 < xxxxx> I'd suggest about 48GB ram for volumes up to 80TB or so.   more 
                if you go above that

15:14 < xxxxx> backuppc is extremely space efficient in its backup volume...  
                it does file level deduplication across the whole thing, so 
                backing up 80 copies of windows only results in one of each file