On Fri, Jun 29, 2012 at 1:59 PM, Brian Edmonds <mornir@xxxxxxxxx> wrote: > On Fri, Jun 29, 2012 at 11:50 AM, Gregory Farnum <greg@xxxxxxxxxxx> wrote: >> If you lose a journal, you lose the OSD. > > Really? Everything? Not just recent commits? I would have hoped it > would just come back up in an old state. Replication should have > already been taking care of regaining redundancy for the stuff that > was on it, particularly the newest stuff that wouldn't return with it > and say "Hi, I'm back." > > I suppose it makes the design easier though. =) Well, actually this depends on the filesystem you're using. With btrfs, the OSD will roll back to a consistent state, but you don't know how out-of-date that state is. (Practically speaking, it's pretty new, but if you were doing any writes it is going to be data loss.) With xfs/ext4/other, the OSD can't create consistency points the same way it can with btrfs, and so the loss of a journal means that it can't repair itself. Sorry for not mentioning the distinction earlier; I didn't think we'd implemented the rollback on btrfs. :) -Greg -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
