Performance issue; cpu has 50%wio

[Volker Borowski]

Hey,

this is a SAP system.

So if everything was OK 10 days ago, and your
storage now shows no defects, why do you even
consider to change something on the storage
as option number one?

I mean if it was bad before that, ok, something could have been missed, but if it
was fine, do not go that way right now.
There are tons of things to check inside SAP
or Oracle first, before it comes to storage
(again: on a system that has been well before!).

If SAP has been patched recently or new
modules have been activated, a significant
amount of new objects could have been
created inside the DB. So may be simply some
DB-stats need to be calculated.

With SAP it is important not only to be on
a current ORACLE patchset, but to have quite
a lot of bugfixes on top of that and a DB
parameterset, that fits the bugfixes as well.

As for what is running right now, check
transactions ST04 / ST04old inside the SAP,
to see what the application is doing right
now and if some indexes could help.

Hope this helps
Volker

[TwoProc]

I would have the DBA's make sure that the current long running queries that are on the system haven't gone wacky due to bad cost statistics. If your stats haven't been updated in a while, this could (and probably is) more of a DBA/Oracle issue than a system issue. To date, I've only seen two occasions where the system itself if responsible for a slowdown, one was a runaway system process(every evident from glance), and the second was the write through cache board on the XP had errored and the XP storage system decided to (correctly)protect itself and its data integirty by turning this feature off until a board level replacement was made.

Other than the two above cases, over the last many years, it's always a case of statistics being out of date on tables, and needing to refreshed so that the optimizer in Oracle could pick the correct execution plan to get the queries done correctly.

Please have your DBA check long running queries, queries consuming the most disk I/O, and run statspack reports to identify the problem.

[Dave Johnson_1]

My 2 cents...
adding swap space on 11.23 IA-64 does not cause/require a reboot of the server. If you want/need to remove a swap file, that requires a reboot, but not adding some.
I have an rx6600 running 11.23 and added swap space last month, no reboot.