On Fri, 22 Feb 2013 11:29:42 -0500 Jerry Feldman <g...@blu.org> wrote:
> So, assume I have 2 physical volumes, /dev/sda and /dev/sdb. > mkfs.btrfs -d raid1 /dev/sda /dev/sdb > What happens if I get a failure on /dev/sdb. > Assume no snapshots. "-d raid1" means mirrored data. Metadata is mirrored by default even on single drive volumes. If /dev/sdb faults then you should lose no data since every extent is replicated on both /dev/sda and /dev/sdb. If a bit error arises on either sda or sdb then a scrub will detect the error and it should automatically correct it using the replica on the other device. If instead you used "-d raid0" (striped data) then the failure of /dev/sdb would result in the unrecoverable loss of half of your file extents. A bit error on sdb will be detected by a scrub but since the data is not replicated it is not possible to automatically correct the error. -- Rich P. _______________________________________________ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss