performance hints (6.2)

[Kris Kennaway]

On Fri, Aug 17, 2007 at 01:35:48PM -0700, Mark Messier wrote:
> >> What does a gstat look like over time?
> 
> Oooh, didn't know about gstat....   it shows disks as being 102% busy  
> at times :-)

gstat's "busy" statistic is entirely meaningless for this context
(rather, it has a meaning but it's not what you think it is).  Instead
you should be looking at the number of transactions/second and the
average time/transaction.  This tells how long processes are waiting
before the disk controller can service the I/O, and you should compare
those numbers to your performance requirements or your expectations
from the hardware.

Your data showed your CPU doing almost no work, so I/O is definitely
your problem though.

Kris
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