What drives are you using? For SCSI RAID, you definitly want deadline
scheduler. That said, even after the switch to deadline, we saw our
Opteron's running way slow (compared to older slower Xeons). Whatever
the problem is, we fought it for quite a while (though difficult to test
too much w/ production dbs) and ended up rolling back to 2.4.
Kevin Burton wrote:
> Kevin Burton wrote:
>
>> Greg Whalin wrote:
>>
>>>
>>> Deadline was much faster. Using sysbench:
>>>
>>> test:
>>> sysbench --num-threads=16 --test=fileio --file-total-size=20G
>>> --file-test-mode=rndrw run
>>
>>
>>
> So... FYI. I rebooted with elevator=deadline as a kernel param.
>
> db2:~# cat /sys/block/sda/queue/scheduler
> noop anticipatory [deadline] cfq
>
> (which I assume means I'm now running deadline. Is there any other way
> to find out?)
>
> And no performance diff. Note that you're benchmarks only show a 20M
> addition overhead. We're about 60x too slow for these drives so I'm not
> sure what could be going on here :-/
>
> Kevin
>
