Re: High load average with PostgreSQL 7.4.2 on debian/ibm eserver. - Mailing list pgsql-performance

From eleven@ludojad.itpp.pl
Subject Re: High load average with PostgreSQL 7.4.2 on debian/ibm eserver.
Date
Msg-id 20040629175227.GA11658@ludojad.itpp.pl
Whole thread Raw
In response to Re: High load average with PostgreSQL 7.4.2 on debian/ibm eserver.  (Marc <identd@gmail.com>)
Responses Re: High load average with PostgreSQL 7.4.2 on debian/ibm eserver.  (Josh Berkus <josh@agliodbs.com>)
List pgsql-performance
On Tue, Jun 29, 2004 at 09:17:36AM -0700, Marc wrote:

> > Performance issue, I'm experiencing here, is somewhat
> > weird - server gets high average load (from 5 up to 15,
> > 8 on average). Standard performance monitoring
> > utilities (like top) show that CPUs are not loaded
> > (below 20%, often near zero).
> So ... you never actually say what the performance issue you
> experience is.  Having a high load average is not necessarily a
> performance issue.

Well, if the server's CPUs are idle and the machine
is starting to hog itself, one can
suspect something bad going on.

> What is it that you want to fix?

Basically, I'm wondering if I'm already on the edge of
performance capabilities of this machine/configuration, or maybe
there's some abnormal behaviour happening (which
could be noticed by somebody from this mailing list, hopefully).

In particular - could someone tell me if those iostat
values can tell if I'm close to upper performance boundary
of fast SCSI (Ultra 320, 15k RPM) disks?

--
11.

pgsql-performance by date:

Previous
From: "Mohan A"
Date:
Subject: suggestions to improve performace
Next
From: "Harald Lau (Sector-X)"
Date:
Subject: Re: no index-usage on aggregate-functions?