From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brad Campbell Subject: Re: High mismatch count on root device - how to best handle? Date: Sun, 01 May 2011 22:50:32 +0800 Message-ID: <4DBD7338.4060206@fnarfbargle.com> References: <4DB71F3E.3040003@turmel.org> <4DB8BEFE.3020009@turmel.org> <20110428053123.B031BD52709@gemini.denx.de> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Mark Knecht Cc: Wolfgang Denk , Phil Turmel , Linux-RAID List-Id: linux-raid.ids On 01/05/11 06:51, Mark Knecht wrote: > On Wed, Apr 27, 2011 at 10:31 PM, Wolfgang Denk wrote: >> Dear Phil Turmel, >> >> In message<4DB8BEFE.3020009@turmel.org> you wrote: >>> >>> Hmmm. Since its not swap, this would make me worry about the hardware. Have you considered shuffling SATA port assignments to see if a pattern shows up? Also consider moving some of the drive power load to another PS. >> >> I do not think this is hardware related. I see this behaviour on at >> least 5 different machines which show no other problems except for the >> mismatch count in the RAID 1 partitins that hold the /boot partition. root@srv:/server# grep . /sys/block/md?/md/mismatch_cnt /sys/block/md0/md/mismatch_cnt:0 /sys/block/md1/md/mismatch_cnt:128 /sys/block/md2/md/mismatch_cnt:0 /sys/block/md3/md/mismatch_cnt:41728 /sys/block/md4/md/mismatch_cnt:896 /sys/block/md5/md/mismatch_cnt:0 /sys/block/md6/md/mismatch_cnt:4352 root@srv:/server# cat /proc/mdstat | grep md[1346] md6 : active raid1 sdp6[0] sdo6[1] md4 : active raid1 sdp3[0] sdo3[1] md3 : active raid1 sdp2[0] sdo2[1] md1 : active raid1 sdp1[0] sdo1[1] root@srv:/server# cat /etc/fstab | grep md[1346] /dev/md1 / ext4 errors=remount-ro,commit=30,noatime 0 1 /dev/md6 /raid0 ext4 defaults,commit=30,noatime 0 1 /dev/md4 /home ext4 defaults,commit=30,noatime 0 1 /dev/md3 none swap sw I see them _all_ the time on RAID1's.. When I configured this system _years_ ago, I did not know any better, so it's a bit of a mish-mash. The machine also has a 10 drive RAID-6 and a 3 drive RAID-5. The only time I've seen mismatches on those is when I used a SIL 3132 controller and it trashed the RAID-6. Brad