Re: High mismatch count on root device - how to best handle?
From: Mark Knecht <hidden>
Date: 2011-05-01 17:13:12
On Sun, May 1, 2011 at 7:50 AM, Brad Campbell [off-list ref] wrote:
On 01/05/11 06:51, Mark Knecht wrote:quoted
On Wed, Apr 27, 2011 at 10:31 PM, Wolfgang Denk[off-list ref] wrote:quoted
Dear Phil Turmel, In message[ref] you wrote:quoted
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
Brad, Thanks very much for sharing the data and your experiences with this. I'll simply ignore it on the RAID1's from now on. Cheers, Mark -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html