[CentOS] 3Ware 9550SX and latency/system responsiveness

Simon Banton centos at web.org.uk
Tue Oct 2 13:38:34 UTC 2007

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

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.


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