[CentOS] Slow RAID Check/high %iowait during check after updgrade from CentOS 6.5 -> CentOS 7.2
cpolish at surewest.net
cpolish at surewest.net
Wed May 25 21:43:25 UTC 2016
On 2016-05-25 19:13, Kelly Lesperance wrote:
> Hdparm didn’t get far:
>
> [root at r1k1 ~] # hdparm -tT /dev/sda
>
> /dev/sda:
> Timing cached reads: Alarm clock
> [root at r1k1 ~] #
Hi Kelly,
Try running 'iostat -xdmc 1'. Look for a single drive that has
substantially greater await than ~10msec. If all the drives
except one are taking 6-8msec, but one is very much more, you've
got a drive that drags down the whole array's performance.
Ignore the very first output from the command - it's an
average of the disk subsystem since boot.
Post a representative output along with the contents /proc/mdstat.
Good luck,
--
Charles Polisher
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