Re: Q: Performance probs SC2000/Sol 2.3/Oracle7.0.16

In article <D1HHwp.6LG_at_cix.compulink.co.uk>, Ravi Kumar <rkumar_at_cix.compulink.co.uk> wrote:
>You haven't mentioned anything about the location of logfiles, whether
>they are on the same disk or what. I am not sure about your mirroring
>strategy.. is it s/w or h/w?
>What is your SGA size ?? Some more info on your db config may be of help.

Mirroring is done with Online-Disk Suite (ODS), so its is software based. The mirrors are cleanly distributed over the controllers etc.

Redo-Logfiles are again mirrored in Oracle onto different disks (they were on filesystems, now they are on raw-devices). This Oracle-Mirroring will be turned off.

When we used filesystems for the datafiles, SGA was 128 MB. With the raw devices we tried various sizes, where something around 520 MB seems to be a limit. The variation didn't help very much in speeding up.

We have now made further test with striping using ODS. It increases the read performance almost linearly. But still we see the effect that no single system resource (disk, memory, CPU) has a contention, and the application stills does not run at expected speed.

Please contact me (joe.ammann_at_zhflur.ubs.ubs.ch) if you need further info.

-- 
Joe