I noticed a few read errors in dmesg, on drives
which are parts of a raid10 array:
sd 0:0:13:0: [sdf] Unhandled sense code
sd 0:0:13:0: [sdf] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
sd 0:0:13:0: [sdf] Sense Key : Medium Error [current]
Info fld=0x880c1d9
sd 0:0:13:0: [sdf] Add. Sense: Unrecovered read error - recommend rewrite the data
sd 0:0:13:0: [sdf] CDB: Read(10): 28 00 08 80 c0 bf 00 01 80 00
end_request: I/O error, dev sdf, sector 142655961
sd 0:0:11:0: [sdd] Unhandled sense code
sd 0:0:11:0: [sdd] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
sd 0:0:11:0: [sdd] Sense Key : Medium Error [current]
Info fld=0x880c3e5
sd 0:0:11:0: [sdd] Add. Sense: Unrecovered read error - recommend rewrite the data
sd 0:0:11:0: [sdd] CDB: Read(10): 28 00 08 80 c2 3f 00 02 00 00
end_request: I/O error, dev sdd, sector 142656485
Both sdf and sdd are parts of the same (raid10) array,
and this array is the only usage for these drives (i.e.,
there's nothing else reading them). Both the mentioned
locations are near the end of the only partition on
these drives:
# partition table of /dev/sdf
unit: sectors
/dev/sdf1 : start= 63, size=142657137, Id=83
(the same partition table is on /dev/sdd too).
Sector 142657200 is the start of the next (non-existing)
partition, so the last sector of the first partition is
142657199.
Now, we've read errors on sectors 142655961 (sdf)
and 142656485 (sdd), which are 1239 and 715 sectors
before the end of the partition, respectively.
The array is this:
# mdadm -E /dev/sdf1
/dev/sdf1:
Magic : a92b4efc
Version : 00.90.00
UUID : 1c49b395:293761c8:4113d295:43412a46
Creation Time : Sun Jun 27 04:37:12 2010
Raid Level : raid10
Used Dev Size : 71328256 (68.02 GiB 73.04 GB)
Array Size : 499297792 (476.17 GiB 511.28 GB)
Raid Devices : 14
Total Devices : 14
Preferred Minor : 11
Update Time : Fri Nov 12 16:55:06 2010
State : clean
Internal Bitmap : present
Active Devices : 14
Working Devices : 14
Failed Devices : 0
Spare Devices : 0
Checksum : 104a3529 - correct
Events : 16790
Layout : near=2, far=1
Chunk Size : 256K
Number Major Minor RaidDevice State
this 10 8 81 10 active sync /dev/sdf1
0 0 8 1 0 active sync /dev/sda1
1 1 8 113 1 active sync /dev/sdh1
2 2 8 17 2 active sync /dev/sdb1
3 3 8 129 3 active sync /dev/sdi1
4 4 8 33 4 active sync /dev/sdc1
5 5 8 145 5 active sync /dev/sdj1
6 6 8 49 6 active sync /dev/sdd1
7 7 8 161 7 active sync /dev/sdk1
8 8 8 65 8 active sync /dev/sde1
9 9 8 177 9 active sync /dev/sdl1
10 10 8 81 10 active sync /dev/sdf1
11 11 8 193 11 active sync /dev/sdm1
12 12 8 97 12 active sync /dev/sdg1
13 13 8 209 13 active sync /dev/sdn1
What's wrong with these read errors? I just verified -
the error persists, i.e. reading the mentioned sectors
using dd produces the same errors again, so there were
no re-writes there.
Can md handle this situation gracefully?
Thanks!
/mjt
--
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
