* Intermittent stalling of all MD IO, Debian buster (4.19.0-16) @ 2021-06-12 12:41 Andy Smith 2021-06-12 13:39 ` Andy Smith 2021-06-16 3:57 ` Guoqing Jiang 0 siblings, 2 replies; 5+ messages in thread From: Andy Smith @ 2021-06-12 12:41 UTC (permalink / raw) To: linux-raid Hi, I've been experiencing this problem intermittently since December of last year after upgrading some existing servers to Debian stable (buster). I can't reproduce it at will and it can sometimes take several months to happen again, although it has just happened twice in 3 days on one host. What happens is that all IO to particular MD devices seems to freeze. At this point I generally have no option but to power cycle the server as an orderly shutdown can't be completed. These servers are Xen hypervisors, and very occasionally I or a guest administrator has been able to shut down a guest and then things seem to become unblocked. I am aware that this could mean it could be a Xen issue and I'm pursuing that angle as well. The version of the Xen hypervisor in use did change as well as the OS upgrade. In terms of logging, this is the sort of thing I get: Jun 12 12:04:40 clockwork kernel: [216427.246183] INFO: task md5_raid1:205 blocked for more than 120 seconds. Jun 12 12:04:40 clockwork kernel: [216427.246995] Not tainted 4.19.0-16-amd64 #1 Debian 4.19.181-1 Jun 12 12:04:40 clockwork kernel: [216427.247852] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Jun 12 12:04:40 clockwork kernel: [216427.248674] md5_raid1 D 0 205 2 0x80000000 Jun 12 12:04:40 clockwork kernel: [216427.249534] Call Trace: Jun 12 12:04:40 clockwork kernel: [216427.250368] __schedule+0x29f/0x840 Jun 12 12:04:40 clockwork kernel: [216427.251788] ? _raw_spin_unlock_irqrestore+0x14/0x20 Jun 12 12:04:40 clockwork kernel: [216427.253078] schedule+0x28/0x80 Jun 12 12:04:40 clockwork kernel: [216427.253945] md_super_wait+0x6e/0xa0 [md_mod] Jun 12 12:04:40 clockwork kernel: [216427.254812] ? finish_wait+0x80/0x80 Jun 12 12:04:40 clockwork kernel: [216427.256139] md_bitmap_wait_writes+0x93/0xa0 [md_mod] Jun 12 12:04:40 clockwork kernel: [216427.256994] ? md_bitmap_get_counter+0x42/0xd0 [md_mod] Jun 12 12:04:40 clockwork kernel: [216427.257787] md_bitmap_daemon_work+0x1f7/0x370 [md_mod] Jun 12 12:04:40 clockwork kernel: [216427.258608] ? md_rdev_init+0xb0/0xb0 [md_mod] Jun 12 12:04:40 clockwork kernel: [216427.259553] md_check_recovery+0x41/0x530 [md_mod] Jun 12 12:04:40 clockwork kernel: [216427.260304] raid1d+0x5c/0xf10 [raid1] Jun 12 12:04:40 clockwork kernel: [216427.261096] ? lock_timer_base+0x67/0x80 Jun 12 12:04:40 clockwork kernel: [216427.261863] ? _raw_spin_unlock_irqrestore+0x14/0x20 Jun 12 12:04:40 clockwork kernel: [216427.262659] ? try_to_del_timer_sync+0x4d/0x80 Jun 12 12:04:40 clockwork kernel: [216427.263436] ? del_timer_sync+0x37/0x40 Jun 12 12:04:40 clockwork kernel: [216427.264189] ? schedule_timeout+0x173/0x3b0 Jun 12 12:04:40 clockwork kernel: [216427.264911] ? md_rdev_init+0xb0/0xb0 [md_mod] Jun 12 12:04:40 clockwork kernel: [216427.265664] ? md_thread+0x94/0x150 [md_mod] Jun 12 12:04:40 clockwork kernel: [216427.266412] ? process_checks+0x4a0/0x4a0 [raid1] Jun 12 12:04:40 clockwork kernel: [216427.267124] md_thread+0x94/0x150 [md_mod] Jun 12 12:04:40 clockwork kernel: [216427.267842] ? finish_wait+0x80/0x80 Jun 12 12:04:40 clockwork kernel: [216427.268539] kthread+0x112/0x130 Jun 12 12:04:40 clockwork kernel: [216427.269231] ? kthread_bind+0x30/0x30 Jun 12 12:04:40 clockwork kernel: [216427.269903] ret_from_fork+0x35/0x40 Jun 12 12:04:40 clockwork kernel: [216427.270590] INFO: task md2_raid1:207 blocked for more than 120 seconds. Jun 12 12:04:40 clockwork kernel: [216427.271260] Not tainted 4.19.0-16-amd64 #1 Debian 4.19.181-1 Jun 12 12:04:40 clockwork kernel: [216427.271942] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Jun 12 12:04:40 clockwork kernel: [216427.272721] md2_raid1 D 0 207 2 0x80000000 Jun 12 12:04:40 clockwork kernel: [216427.273432] Call Trace: Jun 12 12:04:40 clockwork kernel: [216427.274172] __schedule+0x29f/0x840 Jun 12 12:04:40 clockwork kernel: [216427.274869] schedule+0x28/0x80 Jun 12 12:04:40 clockwork kernel: [216427.275543] io_schedule+0x12/0x40 Jun 12 12:04:40 clockwork kernel: [216427.276208] wbt_wait+0x205/0x300 Jun 12 12:04:40 clockwork kernel: [216427.276861] ? wbt_wait+0x300/0x300 Jun 12 12:04:40 clockwork kernel: [216427.277503] rq_qos_throttle+0x31/0x40 Jun 12 12:04:40 clockwork kernel: [216427.278193] blk_mq_make_request+0x111/0x530 Jun 12 12:04:40 clockwork kernel: [216427.278876] generic_make_request+0x1a4/0x400 Jun 12 12:04:40 clockwork kernel: [216427.279657] ? try_to_wake_up+0x54/0x470 Jun 12 12:04:40 clockwork kernel: [216427.280400] submit_bio+0x45/0x130 Jun 12 12:04:40 clockwork kernel: [216427.281136] ? md_super_write.part.63+0x90/0x120 [md_mod] Jun 12 12:04:40 clockwork kernel: [216427.281788] md_update_sb.part.65+0x3a8/0x8e0 [md_mod] Jun 12 12:04:40 clockwork kernel: [216427.282480] ? md_rdev_init+0xb0/0xb0 [md_mod] Jun 12 12:04:40 clockwork kernel: [216427.283106] md_check_recovery+0x272/0x530 [md_mod] Jun 12 12:04:40 clockwork kernel: [216427.283738] raid1d+0x5c/0xf10 [raid1] Jun 12 12:04:40 clockwork kernel: [216427.284345] ? __schedule+0x2a7/0x840 Jun 12 12:04:40 clockwork kernel: [216427.284939] ? md_rdev_init+0xb0/0xb0 [md_mod] Jun 12 12:04:40 clockwork kernel: [216427.285522] ? schedule+0x28/0x80 Jun 12 12:04:40 clockwork kernel: [216427.286121] ? schedule_timeout+0x26d/0x3b0 Jun 12 12:04:40 clockwork kernel: [216427.286702] ? __schedule+0x2a7/0x840 Jun 12 12:04:40 clockwork kernel: [216427.287279] ? md_rdev_init+0xb0/0xb0 [md_mod] Jun 12 12:04:40 clockwork kernel: [216427.287871] ? md_thread+0x94/0x150 [md_mod] Jun 12 12:04:40 clockwork kernel: [216427.288458] ? process_checks+0x4a0/0x4a0 [raid1] Jun 12 12:04:40 clockwork kernel: [216427.289062] md_thread+0x94/0x150 [md_mod] Jun 12 12:04:40 clockwork kernel: [216427.289663] ? finish_wait+0x80/0x80 Jun 12 12:04:40 clockwork kernel: [216427.290288] kthread+0x112/0x130 Jun 12 12:04:40 clockwork kernel: [216427.290858] ? kthread_bind+0x30/0x30 Jun 12 12:04:40 clockwork kernel: [216427.291433] ret_from_fork+0x35/0x40 Anyone seen anything like this before or have any suggestions for what to try next? It's not really feasible for me to try to see if it happens without running as a Xen dom0 because even if it doesn't happen for 2 months I won't have confidence… Thanks, Andy ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Intermittent stalling of all MD IO, Debian buster (4.19.0-16) 2021-06-12 12:41 Intermittent stalling of all MD IO, Debian buster (4.19.0-16) Andy Smith @ 2021-06-12 13:39 ` Andy Smith 2021-06-16 3:57 ` Guoqing Jiang 1 sibling, 0 replies; 5+ messages in thread From: Andy Smith @ 2021-06-12 13:39 UTC (permalink / raw) To: linux-raid On Sat, Jun 12, 2021 at 12:41:57PM +0000, Andy Smith wrote: > Hi, > > I've been experiencing this problem intermittently since December of > last year after upgrading some existing servers to Debian stable > (buster). I can't reproduce it at will and it can sometimes take > several months to happen again, although it has just happened twice > in 3 days on one host. I was in a bit of a rush when I dashed that email off. Here's some more information about the typical configuration of these servers. $ uname -a Linux clockwork 4.19.0-16-amd64 #1 SMP Debian 4.19.181-1 (2021-03-19) x86_64 GNU/Linux $ mdadm --version mdadm - v4.1 - 2018-10-01 Most of these servers have spent about 5 years running on earlier versions of Debian, notably the full Debian jessie release cycle, without issue. I've only started having issues after upgrading to Debian buster. I will omit details of all member devices as I'm not getting issues with IO errors, dropouts etc. Most of the servers just have two SATA SSDs although I am also seeing this on more complex setups. $ cat /proc/mdstat Personalities : [raid1] [linear] [multipath] [raid0] [raid6] [raid5] [raid4] [raid10] md5 : active raid1 sdb5[1] sda5[0] 3742779392 blocks super 1.2 [2/2] [UU] bitmap: 14/28 pages [56KB], 65536KB chunk md1 : active raid1 sdb1[1] sda1[0] 975296 blocks super 1.2 [2/2] [UU] md2 : active raid1 sda2[0] sdb2[1] 4878336 blocks super 1.2 [2/2] [UU] md3 : active (auto-read-only) raid1 sdb3[1] sda3[0] 1951744 blocks super 1.2 [2/2] [UU] unused devices: <none> $ sudo smartctl -i /dev/sda smartctl 6.6 2017-11-05 r4594 [x86_64-linux-4.19.0-16-amd64] (local build) Copyright (C) 2002-17, Bruce Allen, Christian Franke, www.smartmontools.org === START OF INFORMATION SECTION === Device Model: SAMSUNG MZ7KH3T8HALS-00005 Serial Number: S47RNA0MC01657 LU WWN Device Id: 5 002538 e09c88bb3 Firmware Version: HXM7404Q User Capacity: 3,840,755,982,336 bytes [3.84 TB] Sector Sizes: 512 bytes logical, 4096 bytes physical Rotation Rate: Solid State Device Form Factor: 2.5 inches Device is: Not in smartctl database [for details use: -P showall] ATA Version is: ACS-4 T13/BSR INCITS 529 revision 5 SATA Version is: SATA 3.2, 6.0 Gb/s (current: 6.0 Gb/s) Local Time is: Sat Jun 12 13:36:47 2021 UTC SMART support is: Available - device has SMART capability. SMART support is: Enabled $ sudo smartctl -i /dev/sdb smartctl 6.6 2017-11-05 r4594 [x86_64-linux-4.19.0-16-amd64] (local build) Copyright (C) 2002-17, Bruce Allen, Christian Franke, www.smartmontools.org === START OF INFORMATION SECTION === Device Model: SAMSUNG MZ7KH3T8HALS-00005 Serial Number: S47RNA0MC01656 LU WWN Device Id: 5 002538 e09c88b8a Firmware Version: HXM7404Q User Capacity: 3,840,755,982,336 bytes [3.84 TB] Sector Sizes: 512 bytes logical, 4096 bytes physical Rotation Rate: Solid State Device Form Factor: 2.5 inches Device is: Not in smartctl database [for details use: -P showall] ATA Version is: ACS-4 T13/BSR INCITS 529 revision 5 SATA Version is: SATA 3.2, 6.0 Gb/s (current: 6.0 Gb/s) Local Time is: Sat Jun 12 13:36:54 2021 UTC Local Time is: Sat Jun 12 13:36:54 2021 UTC SMART support is: Available - device has SMART capability. SMART support is: Enabled At this point it would be really helpful fi Ic ould even narrow it down to "Xen problem" or "dom0 kernel problem". :( Cheers, Andy ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Intermittent stalling of all MD IO, Debian buster (4.19.0-16) 2021-06-12 12:41 Intermittent stalling of all MD IO, Debian buster (4.19.0-16) Andy Smith 2021-06-12 13:39 ` Andy Smith @ 2021-06-16 3:57 ` Guoqing Jiang 2021-06-16 15:05 ` Andy Smith 1 sibling, 1 reply; 5+ messages in thread From: Guoqing Jiang @ 2021-06-16 3:57 UTC (permalink / raw) To: linux-raid Hi, On 6/12/21 8:41 PM, Andy Smith wrote: > Hi, > > I've been experiencing this problem intermittently since December of > last year after upgrading some existing servers to Debian stable > (buster). I can't reproduce it at will and it can sometimes take > several months to happen again, although it has just happened twice > in 3 days on one host. > > What happens is that all IO to particular MD devices seems to > freeze. At this point I generally have no option but to power cycle > the server as an orderly shutdown can't be completed. > > These servers are Xen hypervisors, and very occasionally I or a > guest administrator has been able to shut down a guest and then > things seem to become unblocked. I am aware that this could mean it > could be a Xen issue and I'm pursuing that angle as well. The > version of the Xen hypervisor in use did change as well as the OS > upgrade. > > In terms of logging, this is the sort of thing I get: > > Jun 12 12:04:40 clockwork kernel: [216427.246183] INFO: task md5_raid1:205 blocked for more than 120 seconds. > Jun 12 12:04:40 clockwork kernel: [216427.246995] Not tainted 4.19.0-16-amd64 #1 Debian 4.19.181-1 > Jun 12 12:04:40 clockwork kernel: [216427.247852] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > Jun 12 12:04:40 clockwork kernel: [216427.248674] md5_raid1 D 0 205 2 0x80000000 > Jun 12 12:04:40 clockwork kernel: [216427.249534] Call Trace: > Jun 12 12:04:40 clockwork kernel: [216427.250368] __schedule+0x29f/0x840 > Jun 12 12:04:40 clockwork kernel: [216427.251788] ? _raw_spin_unlock_irqrestore+0x14/0x20 > Jun 12 12:04:40 clockwork kernel: [216427.253078] schedule+0x28/0x80 > Jun 12 12:04:40 clockwork kernel: [216427.253945] md_super_wait+0x6e/0xa0 [md_mod] > Jun 12 12:04:40 clockwork kernel: [216427.254812] ? finish_wait+0x80/0x80 > Jun 12 12:04:40 clockwork kernel: [216427.256139] md_bitmap_wait_writes+0x93/0xa0 [md_mod] > Jun 12 12:04:40 clockwork kernel: [216427.256994] ? md_bitmap_get_counter+0x42/0xd0 [md_mod] > Jun 12 12:04:40 clockwork kernel: [216427.257787] md_bitmap_daemon_work+0x1f7/0x370 [md_mod] > Jun 12 12:04:40 clockwork kernel: [216427.258608] ? md_rdev_init+0xb0/0xb0 [md_mod] > Jun 12 12:04:40 clockwork kernel: [216427.259553] md_check_recovery+0x41/0x530 [md_mod] > Jun 12 12:04:40 clockwork kernel: [216427.260304] raid1d+0x5c/0xf10 [raid1] > Jun 12 12:04:40 clockwork kernel: [216427.261096] ? lock_timer_base+0x67/0x80 > Jun 12 12:04:40 clockwork kernel: [216427.261863] ? _raw_spin_unlock_irqrestore+0x14/0x20 > Jun 12 12:04:40 clockwork kernel: [216427.262659] ? try_to_del_timer_sync+0x4d/0x80 > Jun 12 12:04:40 clockwork kernel: [216427.263436] ? del_timer_sync+0x37/0x40 > Jun 12 12:04:40 clockwork kernel: [216427.264189] ? schedule_timeout+0x173/0x3b0 > Jun 12 12:04:40 clockwork kernel: [216427.264911] ? md_rdev_init+0xb0/0xb0 [md_mod] > Jun 12 12:04:40 clockwork kernel: [216427.265664] ? md_thread+0x94/0x150 [md_mod] > Jun 12 12:04:40 clockwork kernel: [216427.266412] ? process_checks+0x4a0/0x4a0 [raid1] > Jun 12 12:04:40 clockwork kernel: [216427.267124] md_thread+0x94/0x150 [md_mod] > Jun 12 12:04:40 clockwork kernel: [216427.267842] ? finish_wait+0x80/0x80 > Jun 12 12:04:40 clockwork kernel: [216427.268539] kthread+0x112/0x130 > Jun 12 12:04:40 clockwork kernel: [216427.269231] ? kthread_bind+0x30/0x30 > Jun 12 12:04:40 clockwork kernel: [216427.269903] ret_from_fork+0x35/0x40 > Jun 12 12:04:40 clockwork kernel: [216427.270590] INFO: task md2_raid1:207 blocked for more than 120 seconds. > Jun 12 12:04:40 clockwork kernel: [216427.271260] Not tainted 4.19.0-16-amd64 #1 Debian 4.19.181-1 > Jun 12 12:04:40 clockwork kernel: [216427.271942] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > Jun 12 12:04:40 clockwork kernel: [216427.272721] md2_raid1 D 0 207 2 0x80000000 > Jun 12 12:04:40 clockwork kernel: [216427.273432] Call Trace: > Jun 12 12:04:40 clockwork kernel: [216427.274172] __schedule+0x29f/0x840 > Jun 12 12:04:40 clockwork kernel: [216427.274869] schedule+0x28/0x80 > Jun 12 12:04:40 clockwork kernel: [216427.275543] io_schedule+0x12/0x40 > Jun 12 12:04:40 clockwork kernel: [216427.276208] wbt_wait+0x205/0x300 > Jun 12 12:04:40 clockwork kernel: [216427.276861] ? wbt_wait+0x300/0x300 > Jun 12 12:04:40 clockwork kernel: [216427.277503] rq_qos_throttle+0x31/0x40 > Jun 12 12:04:40 clockwork kernel: [216427.278193] blk_mq_make_request+0x111/0x530 > Jun 12 12:04:40 clockwork kernel: [216427.278876] generic_make_request+0x1a4/0x400 > Jun 12 12:04:40 clockwork kernel: [216427.279657] ? try_to_wake_up+0x54/0x470 > Jun 12 12:04:40 clockwork kernel: [216427.280400] submit_bio+0x45/0x130 > Jun 12 12:04:40 clockwork kernel: [216427.281136] ? md_super_write.part.63+0x90/0x120 [md_mod] > Jun 12 12:04:40 clockwork kernel: [216427.281788] md_update_sb.part.65+0x3a8/0x8e0 [md_mod] > Jun 12 12:04:40 clockwork kernel: [216427.282480] ? md_rdev_init+0xb0/0xb0 [md_mod] > Jun 12 12:04:40 clockwork kernel: [216427.283106] md_check_recovery+0x272/0x530 [md_mod] > Jun 12 12:04:40 clockwork kernel: [216427.283738] raid1d+0x5c/0xf10 [raid1] > Jun 12 12:04:40 clockwork kernel: [216427.284345] ? __schedule+0x2a7/0x840 > Jun 12 12:04:40 clockwork kernel: [216427.284939] ? md_rdev_init+0xb0/0xb0 [md_mod] > Jun 12 12:04:40 clockwork kernel: [216427.285522] ? schedule+0x28/0x80 > Jun 12 12:04:40 clockwork kernel: [216427.286121] ? schedule_timeout+0x26d/0x3b0 > Jun 12 12:04:40 clockwork kernel: [216427.286702] ? __schedule+0x2a7/0x840 > Jun 12 12:04:40 clockwork kernel: [216427.287279] ? md_rdev_init+0xb0/0xb0 [md_mod] > Jun 12 12:04:40 clockwork kernel: [216427.287871] ? md_thread+0x94/0x150 [md_mod] > Jun 12 12:04:40 clockwork kernel: [216427.288458] ? process_checks+0x4a0/0x4a0 [raid1] > Jun 12 12:04:40 clockwork kernel: [216427.289062] md_thread+0x94/0x150 [md_mod] > Jun 12 12:04:40 clockwork kernel: [216427.289663] ? finish_wait+0x80/0x80 > Jun 12 12:04:40 clockwork kernel: [216427.290288] kthread+0x112/0x130 > Jun 12 12:04:40 clockwork kernel: [216427.290858] ? kthread_bind+0x30/0x30 > Jun 12 12:04:40 clockwork kernel: [216427.291433] ret_from_fork+0x35/0x40 The above looks like the bio for sb write was throttled by wbt, which caused the first calltrace. I am wondering if there were intensive IOs happened to the underlying device of md5, which triggered wbt to throttle sb write, or can you access the underlying device directly? And there was a report [1] for raid5 which may related to wbt throttle as well, not sure if the change [2] could help or not. [1]. https://lore.kernel.org/linux-raid/d3fced3f-6c2b-5ffa-fd24-b24ec6e7d4be@xmyslivec.cz/ [2]. https://lore.kernel.org/linux-raid/cb0f312e-55dc-cdc4-5d2e-b9b415de617f@gmail.com/ Thanks, Guoqing ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Intermittent stalling of all MD IO, Debian buster (4.19.0-16) 2021-06-16 3:57 ` Guoqing Jiang @ 2021-06-16 15:05 ` Andy Smith 2021-06-18 5:35 ` Guoqing Jiang 0 siblings, 1 reply; 5+ messages in thread From: Andy Smith @ 2021-06-16 15:05 UTC (permalink / raw) To: linux-raid Hi Guoqing, Thanks for looking at this. On Wed, Jun 16, 2021 at 11:57:33AM +0800, Guoqing Jiang wrote: > The above looks like the bio for sb write was throttled by wbt, which caused > the first calltrace. > I am wondering if there were intensive IOs happened to the > underlying device of md5, which triggered wbt to throttle sb > write, or can you access the underlying device directly? Next time it occurs I can check if I am able to read from the SSDs that make up the MD device, if that information would be helpful. I have never been able to replicate the problem in a test environment so it is likely that it needs to be under heavy load for it to happen. > And there was a report [1] for raid5 which may related to wbt throttle as > well, not sure if the > change [2] could help or not. > > [1]. https://lore.kernel.org/linux-raid/d3fced3f-6c2b-5ffa-fd24-b24ec6e7d4be@xmyslivec.cz/ > [2]. https://lore.kernel.org/linux-raid/cb0f312e-55dc-cdc4-5d2e-b9b415de617f@gmail.com/ All of my MD arrays tend to be RAID-1 or RAID-10, two devices, no journal, internal bitmap. I see the reporter of this problem was using RAID-6 with an external write journal. I can still build a kernel with this patch and try it out, if you think it could possibly help. The long time between incidents obviously makes things extra challenging. The next step I have taken is to put the buster-backports kernel package (5.10.24-1~bpo10+1) on two test servers, and will also boot the production hosts into this if they should experience the problem again. Thanks, Andy ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Intermittent stalling of all MD IO, Debian buster (4.19.0-16) 2021-06-16 15:05 ` Andy Smith @ 2021-06-18 5:35 ` Guoqing Jiang 0 siblings, 0 replies; 5+ messages in thread From: Guoqing Jiang @ 2021-06-18 5:35 UTC (permalink / raw) To: linux-raid Hi Andy, On 6/16/21 11:05 PM, Andy Smith wrote: > Hi Guoqing, > > Thanks for looking at this. > > On Wed, Jun 16, 2021 at 11:57:33AM +0800, Guoqing Jiang wrote: >> The above looks like the bio for sb write was throttled by wbt, which caused >> the first calltrace. >> I am wondering if there were intensive IOs happened to the >> underlying device of md5, which triggered wbt to throttle sb >> write, or can you access the underlying device directly? > Next time it occurs I can check if I am able to read from the SSDs > that make up the MD device, if that information would be helpful. > > I have never been able to replicate the problem in a test > environment so it is likely that it needs to be under heavy load for > it to happen. I guess so, and a reliable reproducer definitely helps us to analysis the root cause. >> And there was a report [1] for raid5 which may related to wbt throttle as >> well, not sure if the >> change [2] could help or not. >> >> [1]. https://lore.kernel.org/linux-raid/d3fced3f-6c2b-5ffa-fd24-b24ec6e7d4be@xmyslivec.cz/ >> [2]. https://lore.kernel.org/linux-raid/cb0f312e-55dc-cdc4-5d2e-b9b415de617f@gmail.com/ > All of my MD arrays tend to be RAID-1 or RAID-10, two devices, no > journal, internal bitmap. I see the reporter of this problem was > using RAID-6 with an external write journal. I can still build a > kernel with this patch and try it out, if you think it could possibly > help. Yes, because both of the two issues have wbt related call traces though raid level is different. > The long time between incidents obviously makes things > extra challenging. > > The next step I have taken is to put the buster-backports kernel > package (5.10.24-1~bpo10+1) on two test servers, and will also boot > the production hosts into this if they should experience the problem > again. Good luck :). Thanks, Guoqing ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-06-18 5:35 UTC | newest] Thread overview: 5+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2021-06-12 12:41 Intermittent stalling of all MD IO, Debian buster (4.19.0-16) Andy Smith 2021-06-12 13:39 ` Andy Smith 2021-06-16 3:57 ` Guoqing Jiang 2021-06-16 15:05 ` Andy Smith 2021-06-18 5:35 ` Guoqing Jiang
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