[SLL] Strange performance problem

[Jesse Keating]

On Saturday 06 January 2007 14:13, Ski Kacoroski wrote:
> some wierd interaction between the system and the 3ware card.  I
> essentially have two almost identical systems with 3ware cards.  One is
> fine (e.g. a du takes a few minutes to complete), the other is not (du
> can take hours).  I have checked for processes with negative niceness
> and for raid rebuilding - both are ok.  strace doesn't show any thing
> other than disk access pausing at times.  I am running sar and there is
> nothing there other than on the slow system it will jump to 99% iowait
> when doing disk I/O.  Next step is to call 3ware.

Don't know if this has been asked before, but have you tried moving the PCI 
slot that the 3ware card is in?  Oft times the slot can make a big 
difference, due to shared IRQs and other resources.

Also ensure that you don't have a degraded array or a disk that is bouncing 
back just quick enough to not get thrown from the array.  Do a disk 
consistency check over night (3ware's 3dm should allow you to do this) and 
replace any drives that fail.

-- 
Jesse Keating RHCE      (geek.j2solutions.net)
Fedora Legacy Team      (www.fedoralegacy.org)
GPG Public Key          (geek.j2solutions.net/jkeating.j2solutions.pub)
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