On Wed, 29 Oct 2008 14:02:04 -0600 Joe Peterson <lavajoe@xxxxxxxxxx> wrote: > Chris Mason wrote: > > On Tue, 2008-10-28 at 16:48 -0700, Stephen Hemminger wrote: > >> I have a system with a pair of small/fast but unreliable scsi drives. > >> I tried setting up a raid1 configuration and using it for builds. > >> Using 2.6.26.7 and btrfs 0.16. When using ext3 (no raid) on same partition, > >> the driver would recalibrate and log something an keep going. But with > >> btrfs it doesn't recover and takes drive offline. > >> > > > > Btrfs doesn't really take drives offline. In the future we'll notice > > that a drive is returning all errors, but for now we'll probably just > > keep beating on it. > > It can also detect when a bad checksum is returned or the drive returns an i/o > error, right? Would the "all-zero" test be a heuristic in case neither of those > happened (but I cannot imagine why the zeros would get by the checksum check)? > > > The IO error handling code in btrfs currently expects it'll be able to > > find at least one good mirror. You're probably hitting some bad > > conditions as it fails to clean up. > > What happens (or rather, will happen) on a regular/non-mirrored btrfs? Would it > then return an i/o error to the user and/or mark a block as bad? In ZFS, the > state of the volume changes, noting an issue (also happens on a scrub), and the > user can check this. What I don't like about ZFS is that the user can clear the > condition, and then it appears OK again until another scrub. > > -Joe I think my problem was that the meta data was mirrored but not the actual data. This lead to total meltdown when data got an error. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
