Re: RAID 10 Benchmark with different I/O schedulers

On Tue, 6 May 2008, Craig James wrote:
> I/O Sched AVG Test1 Test2
> --------- ----- ----- -----
> cfq 705 695 715
> noop 758 769 747
> deadline 741 705 775
> anticipatory 494 477 511

Interesting. That contrasts with some tests I did a while back on a
16-disc RAID-0, where noop, deadline, and anticipatory were all identical
in performance, with cfq being significantly slower. Admittedly, the disc
test was single-process, which is probably why the anticipatory behaviour
didn't kick in. You are seeing a little bit of degradation with cfq - I
guess it's worse the bigger the disc subsystem you have.

Matthew

--
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