I can't umount the zfs brick filesystem even if I stopped the glusterfs on the bad node. Besides, the bad data now seems propagated to the good brick. Can I treat the node is just gone bad? On Wed, Jan 9, 2013 at 9:34 AM, Todd Pfaff <pfaff at rhpcs.mcmaster.ca> wrote: > Liang, > > I suppose my choice of words was misleading. What I mean is: > > - unmount the corrupted brick filesystem > - try to check and repair the brick filesystem > - if repair fails, re-create the filesystem > - remount the brick filesystem > > but, as I said, I'm not very familiar with zfs. Based on my quick glance > at some zfs documentation it sounds to me like online zfs check-and-repair > may be possible (this is oracle zfs documentation and I have no idea how > the linux zfs implementation compares): > > http://docs.oracle.com/cd/**E23823_01/html/819-5461/gbbwa.**html<http://docs.oracle.com/cd/E23823_01/html/819-5461/gbbwa.html> > > but since you're a zfs user you likely already know much more about zfs > than I do. > > Todd > > > On Wed, 9 Jan 2013, 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> >> 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> >> 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<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 >> >> >> >> >> >> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://supercolony.gluster.org/pipermail/gluster-users/attachments/20130110/21237cc1/attachment.html>
