From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Ross Subject: Re: RAID extremely slow Date: Wed, 25 Jul 2012 22:00:47 -0700 Message-ID: <5010CEFF.5030606@familyross.net> References: <501078B2.8070707@familyross.net> <501096C3.5060700@turmel.org> <5010A386.4080209@familyross.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5010A386.4080209@familyross.net> Sender: linux-raid-owner@vger.kernel.org To: Phil Turmel Cc: linux-kernel@vger.kernel.org, linux-raid List-Id: linux-raid.ids >> >>> unused devices: >>> >>> # cat /proc/sys/dev/raid/speed_limit_min >>> 10000 >> MD is unable to reach its minimum rebuild rate while other system >> activity is ongoing. You might want to lower this number to see if that >> gets you out of the stalls. >> >> Or temporarily shut down mythtv. > > I will try lowering those numbers next time this happens, which will > probably be within the next day or two. That's about how often this > happens. Unfortunately, it has happened again, with speeds at near zero. # cat /proc/mdstat Personalities : [raid6] [raid5] [raid4] md0 : active raid6 sdh1[0] sdd1[9] sde1[10] sdb1[6] sdi1[7] sdc1[4] sdf1[3] sdg1[8] sdj1[1] 6837311488 blocks super 1.2 level 6, 512k chunk, algorithm 2 [9/9] [UUUUUUUUU] [=>...................] resync = 8.3% (81251712/976758784) finish=1057826.4min speed=14K/sec unused devices: atop doesn't show ANY activity on the raid device or the individual drives. http://img687.imageshack.us/img687/2913/screenshotfrom201207252.png Also, I tried writing to a test file with the following command, and it hangs. I let it go for about 30 minutes, with no change. # dd if=/dev/zero of=test bs=1M count=1 dmesg only reports hung tasks. It doesn't report any other problems. Here's my dmesg output: http://pastebin.ca/2174778 I'm going to try rebooting into single user mode, and see if the rebuild succeeds without stalling. -- Kevin