> > On Tue, 13 Dec 2011 13:35:46 -0500 > > "Peter M. Petrakis" <peter.petrakis@canonical.com> wrote > What distro and kernel on you on? 2.6.32-71.29.1.el6.x86_64 (CentOS 6) > > Copying the entire LVs sequentially saw no problems. Later when I > > tried to rsync to the LVs the problem showed itself. > > That's remarkable as it removes the fs from the equation. What > fs are you using? ext3 > Not a bad idea. Returning to the backtrace: ... > raid5_quiesce should have been straight forward > > http://lxr.linux.no/linux+v3.1.5/drivers/md/raid5.c#L5422 Interesting. Not that I speak kernel, but I may have to learn. Please note the other partial stack trace included refers to a different function. Dec 13 09:15:52 clonebox3 kernel: Call Trace: Dec 13 09:15:52 clonebox3 kernel: [<ffffffffa01feca5>] raid5_quiesce+0x125/0x1a0 [raid456] Dec 13 09:15:52 clonebox3 kernel: [<ffffffff8105c580>] ? default_wake_function+0x0/0x20 Dec 13 09:15:52 clonebox3 kernel: [<ffffffff810563f3>] ? __wake_up+0x53/0x70 -- Dec 13 09:15:52 clonebox3 kernel: Call Trace: Dec 13 09:15:52 clonebox3 kernel: [<ffffffff814c9a53>] io_schedule+0x73/0xc0 Dec 13 09:15:52 clonebox3 kernel: [<ffffffffa0009a15>] sync_io+0xe5/0x180 [dm_mod] Dec 13 09:15:52 clonebox3 kernel: [<ffffffff81241982>] ? generic_make_request+0x1b2/0x4f0 -- Dec 13 09:15:52 clonebox3 kernel: Call Trace: Dec 13 09:15:52 clonebox3 kernel: [<ffffffffa00046ec>] ? dm_table_unplug_all+0x5c/0xd0 [dm_mod] Dec 13 09:15:52 clonebox3 kernel: [<ffffffff8109bba9>] ? ktime_get_ts+0xa9/0xe0 Dec 13 09:15:52 clonebox3 kernel: [<ffffffff8119e960>] ? sync_buffer+0x0/0x50 an earlier occurrence: Dec 5 23:31:34 clonebox3 kernel: Call Trace: Dec 5 23:31:34 clonebox3 kernel: [<ffffffff8134ac7d>] ? scsi_setup_blk_pc_cmnd+0x13d/0x170 Dec 5 23:31:34 clonebox3 kernel: [<ffffffffa01e7ca5>] raid5_quiesce+0x125/0x1a0 [raid456] Dec 5 23:31:34 clonebox3 kernel: [<ffffffff8105c580>] ? default_wake_function+0x0/0x20 -- Dec 5 23:31:34 clonebox3 kernel: Call Trace: Dec 5 23:31:34 clonebox3 kernel: [<ffffffffa00098fb>] ? dispatch_io+0x22b/0x260 [dm_mod] Dec 5 23:31:34 clonebox3 kernel: [<ffffffff814c9a53>] io_schedule+0x73/0xc0 Dec 5 23:31:34 clonebox3 kernel: [<ffffffffa0009a15>] sync_io+0xe5/0x180 [dm_mod] -- Dec 5 23:31:34 clonebox3 kernel: Call Trace: Dec 5 23:31:34 clonebox3 kernel: [<ffffffff81267d7e>] ? __sg_alloc_table+0x7e/0x130 Dec 5 23:31:34 clonebox3 kernel: [<ffffffffa01e7ca5>] raid5_quiesce+0x125/0x1a0 [raid456] Dec 5 23:31:34 clonebox3 kernel: [<ffffffff8105c580>] ? default_wake_function+0x0/0x20 -- Dec 5 23:31:35 clonebox3 kernel: Call Trace: Dec 5 23:31:35 clonebox3 kernel: [<ffffffffa00098fb>] ? dispatch_io+0x22b/0x260 [dm_mod] Dec 5 23:31:35 clonebox3 kernel: [<ffffffff814c9a53>] io_schedule+0x73/0xc0 Dec 5 23:31:35 clonebox3 kernel: [<ffffffffa0009a15>] sync_io+0xe5/0x180 [dm_mod] -- Dec 5 23:31:35 clonebox3 kernel: Call Trace: Dec 5 23:31:35 clonebox3 kernel: [<ffffffffa01e7ca5>] raid5_quiesce+0x125/0x1a0 [raid456] Dec 5 23:31:35 clonebox3 kernel: [<ffffffff8105c580>] ? default_wake_function+0x0/0x20 Dec 5 23:31:35 clonebox3 kernel: [<ffffffffa01f00c1>] make_request+0x501/0x520 [raid456] -- Dec 5 23:31:35 clonebox3 kernel: Call Trace: Dec 5 23:31:35 clonebox3 kernel: [<ffffffffa00098fb>] ? dispatch_io+0x22b/0x260 [dm_mod] Dec 5 23:31:35 clonebox3 kernel: [<ffffffff814c9a53>] io_schedule+0x73/0xc0 Dec 5 23:31:35 clonebox3 kernel: [<ffffffffa0009a15>] sync_io+0xe5/0x180 [dm_mod] -- Dec 5 23:31:35 clonebox3 kernel: Call Trace: Dec 5 23:31:35 clonebox3 kernel: [<ffffffff81091eb6>] ? autoremove_wake_function+0x16/0x40 Dec 5 23:31:35 clonebox3 kernel: [<ffffffff810500e9>] ? __wake_up_common+0x59/0x90 Dec 5 23:31:35 clonebox3 kernel: [<ffffffff8109218e>] ? prepare_to_wait+0x4e/0x80 > At this point I think you might have more of an MD issue than > anything else. If you could take MD out of the picture by using a > single disk or use a HW RAID, that would be a really useful data > point. I _THINK_ it was all hardware RAID when this happened before, but I can't be sure. -- Ray Morris support@bettercgi.com Strongbox - The next generation in site security: http://www.bettercgi.com/strongbox/ Throttlebox - Intelligent Bandwidth Control http://www.bettercgi.com/throttlebox/ Strongbox / Throttlebox affiliate program: http://www.bettercgi.com/affiliates/user/register.php On Tue, 13 Dec 2011 17:54:02 -0500 "Peter M. Petrakis" <peter.petrakis@canonical.com> wrote: > > > On 12/13/2011 03:10 PM, Ray Morris wrote: > > > > On Tue, 13 Dec 2011 13:35:46 -0500 > > "Peter M. Petrakis" <peter.petrakis@canonical.com> wrote: > > > > > >> Do you by any chance have active LVM snapshots? If so how many and > >> how long have they been provisioned for? > > > > I forgot to mention that. There are now three snapshots, one on > > each of > > What distro and kernel on you on? > > > three LVs, that have been provisioned for a few hours. These LVs > > aren't in active use, but are backups, synced daily. So basically > > the only activity is rsync once daily, bandwidth limited to be > > fairly slow. One logical volume that locked up when trying to write > > to it had a snapshot. > > LVM snapshots can be very I/O intensive, even when you're not > directly using them. > > > > Prior to this most recent rebuild, there were a lot of snap shots - > > three on each of fifteen LVs. I replaced that VG with a fresh one > > and it seemed to work for a while. I thought the problem was likely > > related to lots of long lived snapshots, but after completely > > rebuilding the VG after deleting all snapshots the problem recurred > > very quickly, before there were many snapshots and before there was > > a lot of IO to the snaps > > > > I realize I'm somewhat abusing snapshots - they weren't designed to > > be long lived. Therefore my "torture test" usage may reveal > > problems that wouldn't happen often with very short lived > > snapshots. > > That's right :). Some have reported as high as 50% impact on > performance. > > > Another similar server has more snapshots on more LVs running the > > same rsyncs without obvious trouble. > > > > I should also have mentioned sequential writes to one LV at a time > > don't seem to trigger the problem. I copied the whole VG one LV > > at a time with: > > dd if=/dev/oldvg/lv1 of=/dev/newvg/lv1 > > > Copying the entire LVs sequentially saw no problems. Later when I > > tried to rsync to the LVs the problem showed itself. > > That's remarkable as it removes the fs from the equation. What > fs are you using? > > > > >>>> filter = [ "a|^/dev/md.*|", "a|^/dev/sd.*|", > >>>> "a|^/dev/etherd/.*|","r|^/dev/ram.*|", "r|block|", "r/.*/" ] > >>> > >> Is it intentional to include sd devices? Just because the MD uses > >> them doesn't mean you have to make allowances for them here. > > > > > > Some /dev/sdX devices were used, but no more and I have now removed > > sd.* and etherd. > > > > > >>> < locking_dir = "/var/lock/lvm" > >>> --- > >>>> locking_dir = "/dev/shm" > >> > >> Why? > > > > This was changed AFTER the problem started. > > Because comment in the file says: > > > > # Local non-LV directory that holds file-based locks while > > commands # are in progress. > > > > Because /var/lock is on an LV, I tried switching it to a directory > > that will never be on an LV. That didn't seem to have any effect. > > Not a bad idea. Returning to the backtrace: > > ... > Dec 13 09:15:52 clonebox3 kernel: [<ffffffffa01feca5>] > raid5_quiesce+0x125/0x1a0 [raid456] Dec 13 09:15:52 clonebox3 kernel: > [<ffffffff8105c580>] ? default_wake_function+0x0/0x20 Dec 13 09:15:52 > clonebox3 kernel: [<ffffffff810563f3>] ? __wake_up+0x53/0x70 Dec 13 > 09:15:52 clonebox3 kernel: [<ffffffffa02070c1>] > make_request+0x501/0x520 [raid456] Dec 13 09:15:52 clonebox3 kernel: > [<ffffffff8102ea69>] ? native_smp_send_reschedule+0x49/0x60 Dec 13 > 09:15:52 clonebox3 kernel: [<ffffffff810508e8>] ? > resched_task+0x68/0x80 Dec 13 09:15:52 clonebox3 kernel: > [<ffffffff813d09fb>] md_make_request+0xcb/0x230 > > Dec 13 09:15:52 clonebox3 kernel: [<ffffffff8105c484>] ? > try_to_wake_up+0x284/0x380 Dec 13 09:15:52 clonebox3 kernel: > [<ffffffff81241982>] generic_make_request+0x1b2/0x4f0 ... > > Dec 13 09:15:52 clonebox3 kernel: [<ffffffffa00029c4>] ? > dm_wait_for_completion+0xd4/0x100 [dm_mod] Dec 13 09:15:52 clonebox3 > kernel: [<ffffffffa0003836>] dm_flush+0x56/0x70 [dm_mod] Dec 13 > 09:15:52 clonebox3 kernel: [<ffffffffa00038a4>] dm_wq_work+0x54/0x200 > [dm_mod] ... Dec 13 09:15:52 clonebox3 kernel: INFO: task > kcopyd:31629 blocked for more than 120 seconds. Dec 13 09:15:52 > clonebox3 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" > disables this message. Dec 13 09:15:52 clonebox3 kernel: > kcopyd D ffff88007b824700 0 31629 2 0x00000080 Dec 13 > 09:15:52 clonebox3 kernel: ffff880044aa7ac0 0000000000000046 > ffff880044aa7a88 ffff880044aa7a84 Dec 13 09:15:52 clonebox3 kernel: > ffff880044aa7ae0 ffff88007b824700 ffff880001e16980 00000001083f7280 > > raid5_quiesce should have been straight forward > > http://lxr.linux.no/linux+v3.1.5/drivers/md/raid5.c#L5422 > > >From the stack context I expect it to in case 2 or 0. It could also > >be stuck on a lock or it > really did stop writes. > > At this point I think you might have more of an MD issue than > anything else. If you could take MD out of the picture by using a > single disk or use a HW RAID, that would be a really useful data > point. > > I would also investigate the health of your RAID. Look back in the > logs for members being ejected and then re-introduced. Also if you > have any scripts that use mdadm to ping the array for status you > might want to stop those too. Sounds like the linux-raid list is your > next stop. > > Peter > > _______________________________________________ > linux-lvm mailing list > linux-lvm@redhat.com > https://www.redhat.com/mailman/listinfo/linux-lvm > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/ > _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
