A follow-up to an earlier post about weird slowness with RAID10,f2 and
3 drives. This morning's "check" operation is proceeding very slowly,
for some reason.
dstat is showing 14-15MB/s worth of read I/O (0 or negligible write
I/O) on each of the 3 drives which comprise the raid10,f2.
According to /proc/mdstat this is the current rate:
[================>....] check = 82.9% (381575040/460057152)
finish=60.6min speed=21554K/sec
The sync_speed_min is 40000, sync_speed_max is 200000, and there is no
other I/O on the system to speak of.
blockdev shows:
blockdev --getra /dev/sdb /dev/sdc /dev/sde
256
256
256
I just now tried setting it to 64K (65536) on each device and that did
not seem to make much difference.
As you may recall from earlier posts, these drives are easily capable
of twice or even three times this rate or more even at the inner
tracks (70-80MB/s each on the outer tracks, 35-40MB/s on the inner
tracks).
What might be going on here?
kernel: 2.6.25.18-0.2-default x86_64
mdadm --detail
/dev/md0:
Version : 0.90
Creation Time : Fri May 23 23:24:20 2008
Raid Level : raid10
Array Size : 460057152 (438.74 GiB 471.10 GB)
Used Dev Size : 306704768 (292.50 GiB 314.07 GB)
Raid Devices : 3
Total Devices : 3
Preferred Minor : 0
Persistence : Superblock is persistent
Intent Bitmap : Internal
Update Time : Mon Dec 15 07:31:11 2008
State : active, recovering
Active Devices : 3
Working Devices : 3
Failed Devices : 0
Spare Devices : 0
Layout : far=2
Chunk Size : 64K
Rebuild Status : 84% complete
UUID : ff4e969d:2f07be4e:8c61e068:8406cdc0
Events : 0.7676
Number Major Minor RaidDevice State
0 8 20 0 active sync /dev/sdb4
1 8 68 1 active sync /dev/sde4
2 8 36 2 active sync /dev/sdc4
--
Jon
--
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
