Comment ZFS (Score 4, Interesting) 303
Having had a few EXT3 filesystems go tits up because they've been quietly borking themselves on a 24/7/365 server being able to do a weekly "zpool scrub" in a 4TB array without the downtime is a beautiful thing. Kernel CIFS with proper ACLs and integration with ZFS snapshots is pretty great as well. When btrfs is released and gets a few miles on it I may switch back. But for now my file server stays OpenSolaris.