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> 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 > >
