On Sun, May 22, 2011 at 09:31:49AM +0000, ed wrote: I've not used ZFS, so I can't compare the two directly. However, btrfs is currently less mature: we recommend having good backups regardless of your filesystem, but we suggest that you be prepared to use them if you're running btrfs. That said, the latest version is pretty stable in normal use. It supports RAID-0, -1 and -10 independently for each of data and metadata, has independently-moutable subvolumes and copy-on-write snapshots, and supports online resize and disk insertion and removal. It's fully checksummed, so if it encounters corrupt data it can tell you, *and* attempt to go and read from the other copy in your RAID-1 (or -10) array -- MD RAID-1 won't do this for you, because it doesn't have the checksums, so it can't tell which copy is good. There's a mode for supporting SSDs. What's not there yet, but planned: a working fsck(*), deduplication, a cross-filesystem replication tool like ZFS's send/receive, RAID-5/6 (in .41, probably), hierarchical storage, per-subvolume RAID options, changing RAID levels, encryption. Hugo. (*) Rumour has it that we'll get the first cut of this at the end of the month. But we've all heard that one before. -- === Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk === PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk --- Is a diversity twice as good as a university? ---