Messages in this thread | | | Date | Sat, 28 Jul 2012 01:34:38 -0700 | From | Kevin Ross <> | Subject | Re: RAID extremely slow |
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On 07/27/2012 09:45 PM, Grant Coady wrote: > On Fri, 27 Jul 2012 14:45:18 -0700, you wrote: > >> On 07/27/2012 12:08 PM, Bill Davidsen wrote: >>> Have you set the io scheduler to deadline on all members of the array? >>> That's kind of "job one" on older kernels. >>> >> I have not, thanks for the tip, I'll look into that now. > Plus I disable the on-drive queuing (NCQ) during startup, right now > I don't have benchmarks to show the difference. This on a six by 1TB > drive RAID6 array I built over a year ago on Slackware64-13.37: > > # cat /etc/rc.d/rc.local > ... > # turn off NCQ on the RAID drives by adjusting queue depth to 1 > n=1 > echo "rc.local: Disable RAID drives' NCQ" > for d in a b c d e f > do > echo " set NCQ depth to $n on sd${d}" > echo $n> /sys/block/sd${d}/device/queue_depth > done > ... > > Maybe you could try that? See if it makes a difference. My drives > are Seagate. > > Grant. >
Does disabling NCQ improve performance?
The suggestion to use kernel 3.4.6 has been working quite well so far, hopefully that fixes the problem. I'll know for sure in a few more days...
Thanks! -- Kevin
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