[CentOS] 3Ware 9550SX and latency/system responsiveness
Ross S. W. Walker
rwalker at medallion.com
Tue Oct 2 13:41:25 UTC 2007
Simon Banton wrote:
>
> At 09:24 -0400 2/10/07, Ross S. W. Walker wrote:
> >Actually the real-real fix was to use the 'deadline' or
> 'noop' scheduler
> >with this card as the default 'cfq' scheduler was designed
> to work with
> >a single drive and not a multiple drive RAID, so it acts as
> a govenor on
> >the amount of IO that a single process can send to the
> device and when
> >you do multiple overlapping IOs performance decreases instead of
> >increases.
>
> Ah - that wasn't actually a complete fix Ross, but it did give a
> noticeable improvement in certain situations. I'm still chasing a
> real real 'general purpose' fix.
I was unaware of that. I thought changing schedulers did it.
What is the recurring performance problem you are seeing?
-Ross
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