It seems to me that what you need to do is replace the failed brick, or simply rebuild the filesystem and let gluster attempt to restore it from a *clean* filesystem. I haven't seen anywhere that allows gluster to actually change the replication count on a live cluster, which is what you seem to be requesting. On 01/09/2013 07:57 AM, Liang Ma wrote: > Todd, > > Thanks for your reply. But how can I take this brick offline? Since > the gluster volume has replicate count 2, it won't allow me to remove > one brick. Is there a command which can take one replicate brick offline? > > Many thanks. > > Liang > > > On Tue, Jan 8, 2013 at 3:02 PM, Todd Pfaff <pfaff at rhpcs.mcmaster.ca > <mailto:pfaff at rhpcs.mcmaster.ca>> wrote: > > Liang, > > I don't claim to know the answer to your question, and my > knowledge of zfs > is minimal at best so I may be way off base here, but it seems to > me that > your attempted random corruption with this command: > > > dd if=/dev/urandom of=/dev/sda6 bs=1024 count=20480 > > is likely going to corrupt the underlying zfs filesystem metadata, not > just file data, and I wouldn't expect gluster to be able to fixed a > brick's corrupted filesystem. Perhaps you now have to take the brick > offline, fix any zfs filesystem errors if possible, bring the > brick back > online and see what then happens with self-heal. > > -- > Todd Pfaff <pfaff at mcmaster.ca <mailto:pfaff at mcmaster.ca>> > http://www.rhpcs.mcmaster.ca/ > > > On Tue, 8 Jan 2013, Liang Ma wrote: > > Hi There, > > I'd like to test and understand the self heal feature of > glusterfs. This is > what I did with 3.3.1-ubuntu1~precise4 on Ubuntu 12.04.1 LTS. > > gluster volume create gtest replica 2 gluster3:/zfs-test > gluster4:/zfs-test > where zfs-test is a zfs pool on partition /dev/sda6 in both nodes. > > To simulate a random corruption on node gluster3 > > dd if=/dev/urandom of=/dev/sda6 bs=1024 count=20480 > > Now zfs detected the corrupted files > > pool: zfs-test > state: ONLINE > status: One or more devices has experienced an error resulting > in data > corruption. Applications may be affected. > action: Restore the file in question if possible. Otherwise > restore the > entire pool from backup. > see: http://zfsonlinux.org/msg/ZFS-8000-8A > scan: none requested > config: > > NAME STATE READ WRITE CKSUM > zfs-test ONLINE 0 0 2.29K > sda6 ONLINE 0 0 4.59K > > errors: Permanent errors have been detected in the following > files: > > /zfs-test/<xattrdir>/trusted.gfid > > /zfs-test/.glusterfs/b0/1e/b01ec17c-14cc-4999-938b-b4a71e358b46 > > /zfs-test/.glusterfs/b0/1e/b01ec17c-14cc-4999-938b-b4a71e358b46/<xat > trdir>/trusted.gfid > > /zfs-test/.glusterfs/dd/8c/dd8c6797-18c3-4f3b-b1ca-86def2b578c5/<xat > trdir>/trusted.gfid > > Now the gluster log file shows the self heal can't fix the > corruption > [2013-01-08 12:46:03.371214] W > [afr-common.c:1196:afr_detect_self_heal_by_iatt] > 2-gtest-replicate-0: > /K.iso: gfid different on subvolume > [2013-01-08 12:46:03.373539] E > [afr-self-heal-common.c:1419:afr_sh_common_lookup_cbk] > 2-gtest-replicate-0: > Missing Gfids for /K.iso > [2013-01-08 12:46:03.385701] E > [afr-self-heal-common.c:2160:afr_self_heal_completion_cbk] > 2-gtest-replicate-0: background gfid self-heal failed on /K.iso > [2013-01-08 12:46:03.385760] W [fuse-bridge.c:292:fuse_entry_cbk] > 0-glusterfs-fuse: 11901: LOOKUP() /K.iso => -1 (No data available) > > where K.iso is one of the sample files affected by the dd command. > > So could anyone tell me what is the best way to repair the > simulated > corruption? > > Thank you. > > Liang > > > > > > _______________________________________________ > Gluster-users mailing list > Gluster-users at gluster.org > http://supercolony.gluster.org/mailman/listinfo/gluster-users -- Daniel Taylor VP Operations Vocal Laboratories, Inc dtaylor at vocalabs.com 612-235-5711
