I got an error last week from a new raid6 array about a mismatch_cnt. I
did some reading online, performed a repair action on the array,
performed a check action, and checked for the mismatch_cnt again. The
number was greatly reduced, but it was still there. According to mdadm,
everything appears to be working fine. All the drives are passing short
tests on smartctl.
What is mismatch_cnt really? Should I even be concerned about this?
The array is giving me 25-30MB/sec performance on an sshfs mount over
the network. With a local copy I can see speeds of 50 to 60MB/sec.
Thanks,
Andrew Falgout
-----> inserting boring details here <-----------
==> checked for mismatch_cnt
cat /sys/block/md1/md/mismatch_cnt
7752
==> performed the repair this way:
echo "repair" >/sys/block/md1/md/sync_action
==> performed the check this way:
echo "check" >/sys/block/md1/md/sync_action
==> Array Details
Array Details as follows:
/dev/md1:
Version : 1.2
Creation Time : Fri Mar 25 20:16:33 2011
Raid Level : raid6
Array Size : 7814047744 (7452.06 GiB 8001.58 GB)
Used Dev Size : 1953511936 (1863.01 GiB 2000.40 GB)
Raid Devices : 6
Total Devices : 6
Persistence : Superblock is persistent
Intent Bitmap : Internal
Update Time : Thu Apr 21 07:35:08 2011
State : active
Active Devices : 6
Working Devices : 6
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 512K
Name : nas.falgout.lan:1 (local to host nas.falgout.lan)
UUID : df03c833:90129ffd:123abdca:6b30c319
Events : 75072
Number Major Minor RaidDevice State
0 8 1 0 active sync /dev/sda1
1 8 81 1 active sync /dev/sdf1
2 8 97 2 active sync /dev/sdg1
3 8 113 3 active sync /dev/sdh1
4 8 129 4 active sync /dev/sdi1
5 8 145 5 active sync /dev/sdj1
Disk Details:
/dev/sda1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x1
Array UUID : df03c833:90129ffd:123abdca:6b30c319
Name : nas.falgout.lan:1 (local to host nas.falgout.lan)
Creation Time : Fri Mar 25 20:16:33 2011
Raid Level : raid6
Raid Devices : 6
Avail Dev Size : 3907025072 (1863.01 GiB 2000.40 GB)
Array Size : 15628095488 (7452.06 GiB 8001.58 GB)
Used Dev Size : 3907023872 (1863.01 GiB 2000.40 GB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
State : clean
Device UUID : 6735ec05:80890fa1:86e03b80:1f5de847
Internal Bitmap : 8 sectors from superblock
Update Time : Thu Apr 21 07:45:17 2011
Checksum : 99fdeb3f - correct
Events : 75072
Layout : left-symmetric
Chunk Size : 512K
Device Role : Active device 0
Array State : AAAAAA ('A' == active, '.' == missing)
/dev/sdf1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x1
Array UUID : df03c833:90129ffd:123abdca:6b30c319
Name : nas.falgout.lan:1 (local to host nas.falgout.lan)
Creation Time : Fri Mar 25 20:16:33 2011
Raid Level : raid6
Raid Devices : 6
Avail Dev Size : 3907025072 (1863.01 GiB 2000.40 GB)
Array Size : 15628095488 (7452.06 GiB 8001.58 GB)
Used Dev Size : 3907023872 (1863.01 GiB 2000.40 GB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
State : clean
Device UUID : e18ce851:efc426b3:cadca5f9:df898fa7
Internal Bitmap : 8 sectors from superblock
Update Time : Thu Apr 21 07:45:17 2011
Checksum : d122a72e - correct
Events : 75072
Layout : left-symmetric
Chunk Size : 512K
Device Role : Active device 1
Array State : AAAAAA ('A' == active, '.' == missing)
/dev/sdg1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x1
Array UUID : df03c833:90129ffd:123abdca:6b30c319
Name : nas.falgout.lan:1 (local to host nas.falgout.lan)
Creation Time : Fri Mar 25 20:16:33 2011
Raid Level : raid6
Raid Devices : 6
Avail Dev Size : 3907025072 (1863.01 GiB 2000.40 GB)
Array Size : 15628095488 (7452.06 GiB 8001.58 GB)
Used Dev Size : 3907023872 (1863.01 GiB 2000.40 GB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
State : clean
Device UUID : 4cff4ab7:8e7c4312:1445828a:f0be7e89
Internal Bitmap : 8 sectors from superblock
Update Time : Thu Apr 21 07:45:17 2011
Checksum : 86d6e94 - correct
Events : 75072
Layout : left-symmetric
Chunk Size : 512K
Device Role : Active device 2
Array State : AAAAAA ('A' == active, '.' == missing)
/dev/sdh1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x1
Array UUID : df03c833:90129ffd:123abdca:6b30c319
Name : nas.falgout.lan:1 (local to host nas.falgout.lan)
Creation Time : Fri Mar 25 20:16:33 2011
Raid Level : raid6
Raid Devices : 6
Avail Dev Size : 3907025072 (1863.01 GiB 2000.40 GB)
Array Size : 15628095488 (7452.06 GiB 8001.58 GB)
Used Dev Size : 3907023872 (1863.01 GiB 2000.40 GB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
State : clean
Device UUID : 05a949c4:ab94a3f4:ae25fe55:8034dbfb
Internal Bitmap : 8 sectors from superblock
Update Time : Thu Apr 21 07:45:17 2011
Checksum : 35a48696 - correct
Events : 75072
Layout : left-symmetric
Chunk Size : 512K
Device Role : Active device 3
Array State : AAAAAA ('A' == active, '.' == missing)
/dev/sdi1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x1
Array UUID : df03c833:90129ffd:123abdca:6b30c319
Name : nas.falgout.lan:1 (local to host nas.falgout.lan)
Creation Time : Fri Mar 25 20:16:33 2011
Raid Level : raid6
Raid Devices : 6
Avail Dev Size : 3907025072 (1863.01 GiB 2000.40 GB)
Array Size : 15628095488 (7452.06 GiB 8001.58 GB)
Used Dev Size : 3907023872 (1863.01 GiB 2000.40 GB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
State : clean
Device UUID : ff0881e7:7e22804f:d0b57eb7:60872ff0
Internal Bitmap : 8 sectors from superblock
Update Time : Thu Apr 21 07:45:17 2011
Checksum : 98d5766 - correct
Events : 75072
Layout : left-symmetric
Chunk Size : 512K
Device Role : Active device 4
Array State : AAAAAA ('A' == active, '.' == missing)
/dev/sdj1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x1
Array UUID : df03c833:90129ffd:123abdca:6b30c319
Name : nas.falgout.lan:1 (local to host nas.falgout.lan)
Creation Time : Fri Mar 25 20:16:33 2011
Raid Level : raid6
Raid Devices : 6
Avail Dev Size : 3907025072 (1863.01 GiB 2000.40 GB)
Array Size : 15628095488 (7452.06 GiB 8001.58 GB)
Used Dev Size : 3907023872 (1863.01 GiB 2000.40 GB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
State : clean
Device UUID : 9a200b64:483f52d0:a3d97d13:39ff95be
Internal Bitmap : 8 sectors from superblock
Update Time : Thu Apr 21 07:45:17 2011
Checksum : 314f2777 - correct
Events : 75072
Layout : left-symmetric
Chunk Size : 512K
Device Role : Active device 5
Array State : AAAAAA ('A' == active, '.' == missing)
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
