On Jan 5, 2014, at 4:48 PM, Chris Murphy <li...@colorremedies.com> wrote:
> > On Jan 5, 2014, at 2:17 PM, Sulla <su...@gmx.at> wrote: > >> -----BEGIN PGP SIGNED MESSAGE----- >> Hash: SHA1 >> >> Dear Chris! >> >> Certainly: I have 3 HDDs, all of which WD20EARS. > > These drives don't have a configurable SCT ERC, so you need to modify the > SCSI block layer timeout: > > echo 120 >/sys/block/sdX/device/timeout > > You also need to schedule regular scrubs at the md level as well. > > echo check > /sys/block/mdX/md/sync_action > cat /sys/block/mdX/mismatch_cnt > > More info about this is in man 4 md, and on the linux-raid list. > >> >> 3904907520 blocks super 1.2 level 5, 8k chunk, algorithm 2 [3/3] [UUU] > > OK so 8KB chunk, 16KB full stripe, so that doesn't apply to what I was > thinking might be the case. The workload is presumably small file sizes, like > a mail server? > > >> any other information I can supply? > > I'm not a developer, I don't know if this problem is known or maybe fixed in > a newer kernel than 3.11.0 - which has been around for 5-6 months. I think > the main suggestion is to try a newer kernel, granted with the configuration > of md, lvm, and btrfs you have three layers that will likely have kernel > changes. I'd make sure you have backups. While this layout is valid and > should work, it's also probably less common and therefore less tested. > > Usually in case of blocking devs want to see sysrq+w issued. The setup is > dmesg -n7, and enable sysrq functions. Then reproduce the block, and during > the block issue w to the sysrq trigger, then capture dmesg contents and post > the block and any other nearby btrfs messages. > > https://www.kernel.org/doc/Documentation/sysrq.txt Also, this thread is pretty cluttered with other conversations by now so I think you're best off starting a new thread with this information, maybe a title of "PROBLEM: btrfs on LVM on md raid, blocking > 120 seconds" Since it's almost inevitable you'd be asked to test with a newer kernel anyway, you might as well go to 3.13rc7 and see if you can reproduce, if reproducible, be specific with the problem report by following this template: https://www.kernel.org/pub/linux/docs/lkml/reporting-bugs.html Chris Murphy-- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
