From: Green, Simon (Simon.Green@EU.ALTRIA.COM)
Date: Mon Jun 30 2003 - 10:28:37 EDT
The only problems I have experienced - other than an actual shortage of
resources - have been due to the wrong vmtune settings. (And remember that
the default settings are NOT good for a database.)
It's worth considering AIO as well, but I've never had a problem with that.
The sort of settings I use are:
/usr/samples/kernel/vmtune -p3 -P8 -b400
That's taken from an 8-way S7A with 8GB memory, running SAP with a 750GB
database. It's quite busy, but has almost no paging. It's based on our
experience and recommendations from SAP.
If you don't have something similar - particularly the -p/-P - then take
care of that before tackling anything else.
When you say the disks are "only 50% busy" what do you mean? If that's
either I/O Wait or % active then I'd say it's on the high side. What sort
of disk subsystem do you have?
Simon Green
Altria ITSC Europe Ltd
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-----Original Message-----
From: Spencer Johnson [mailto:Spencer.Johnson@2020LOG.COM]
Sent: 30 June 2003 14:49
To: aix-l@Princeton.EDU
Subject: S85 not quite right !!
Hi list,
I have a slight problem / issue, this is related to an 7017-S85 server,
connected to F20 ESS. The server is a 6W - 8 GB RAM running Oracle 8.1.7.4
with
database instance of approx. 1 TB.
The problem is that most operations (coping files, etc) cause the system to
page and send the CPU's into Wait state constantly, I have logged a call
with IBM and they have
come back with a few suggestions of changing vmtune parameters.
Oracle is tuned to allow for 6W processors but I feel that the O/S is being
restricted by something. The disks do not perform that much work (only 50%
busy at max).
The O/S is currently at 4.3.3 ML 10, but am considering going to ML 11.
Has anyone out there had similar experiences and how have they been
overcome.
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