On Tue, 10 Apr 2007 09:41:27 -0700, WilArtman wrote:

> Looking for some info and direction for tuning IO on an AIX 5.3 system
> running on a p570. The output of "iostat -D" provides a counter named
> "sqfull", which (by way of the man page) indicates the number of times
> the service queue becomes full (disk not accepting any more service
> requests). We have an IO intensive application and the numbers coming
> up here are in the hundreds per second. Nothing I can find on the AIX
> documentation site covers this as an issuee.
>
> Any info would be greatly appreciated.
>
> Thanks
>
> Wil

For most types of disk devices and subsystems, you can probably tune the
depth of the queue on each disk device. Depending on your application,
you may also be filling the asychronous I/O queue. Adding more AIO
threads and/or changing the queue depth at that level could provide you
with a boost...

-Chris