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#1 (**permalink**) 01-05-2008, 06:19 AM

We are using aix 5.3 ML 1 on 570 (power 5). We have 16 GB of Ram and 8
CPU's. This is an Oracle application machine.
We are using JFS2. We used to have dio but we cancel it because
we have been told so by HITACHI (our disk customer)
Our problem is that the Disks on which the paging space resides
are 100% busy sometimes. The lsps -a shows that only 35 percent
of the paging space is used.
I have read some staff here about problems with oracle application
but this looks to me as aix problem.

Any Idea

#2 (**permalink**) 01-05-2008, 06:19 AM

What are your maxperm / minperm settings ? use vmo -L or vmstat -v ..
what size is your SGA and please paste some "vmstat 1 20" output when
the system is under load.

Rgds
Mark Taylor

#3 (**permalink**) 01-05-2008, 06:19 AM

mtfuri@fibimail.co.il wrote:
> We are using aix 5.3 ML 1 on 570 (power 5). We have 16 GB of Ram and
8
> CPU's. This is an Oracle application machine.
> We are using JFS2. We used to have dio but we cancel it because
> we have been told so by HITACHI (our disk customer)
> Our problem is that the Disks on which the paging space resides
> are 100% busy sometimes. The lsps -a shows that only 35 percent
> of the paging space is used.
> I have read some staff here about problems with oracle application
> but this looks to me as aix problem.
>
> Any Idea

I've been having problems with paging as well since upgrading to AIX
5.3 ML1. I don't have Oracle running on the box either (just Legato).
I've been working with IBM and they keep saying it's an application
problem as they are seeing the system run short of memory and paging
before it basically locks up (unable to fork). Interesting that
someone else is having a similar problem.

#4 (**permalink**) 01-05-2008, 06:20 AM

We do not have this problem any more (good news).
We can not tell fore sure why (bad news).
What we did is loer the maxperm and maxclient paramerets to 40.
But I beleive that what actually helped us was bringing the Oracle
Application Down.
(probably some java memory leaks....???)
I we shall see that this problem happen again I shall try to bring more
details.
Anyhow Thank you all.
Uri

#5 (**permalink**) 01-05-2008, 06:21 AM

Hi,

if I guess right you run you Oracle DB on Filesystems not raw LV?
If so it is a good idea to reduce the minperm and maxperm settings.
We use for our DB servers with lot of memory settings like
minperm% = 3 and maxperm% = 8

If you do not do this tuning, keep in mind that the database buffer
cache could be
paged out because the VMM file cache is also caching the database
files. This
would require the use of real memory, leaving less memory for the
database buffer
cache.

HTH
Axel

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Paging problem on AIX 5.3