Subject: Re: Really bad diskio
From: "Jeffrey W. Baker" <jwbaker@acm.org>
To: Ron Wills <ron@rwsoft.ca>
Cc: pgsql-performance@postgresql.org
In-Reply-To: <8764vbby7r.wl%ron@rwsoft.ca>
References: <8764vbby7r.wl%ron@rwsoft.ca>
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Date: Fri, 15 Jul 2005 14:00:07 -0700
Message-Id: <1121461207.28449.8.camel@toonses.gghcwest.com>
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On Fri, 2005-07-15 at 14:39 -0600, Ron Wills wrote:
> Hello all
> 
>   I'm running a postgres 7.4.5, on a dual 2.4Ghz Athlon, 1Gig RAM and
> an 3Ware SATA raid. Currently the database is only 16G with about 2
> tables with 500000+ row, one table 200000+ row and a few small
> tables. The larger tables get updated about every two hours. The
> problem I having with this server (which is in production) is the disk
> IO. On the larger tables I'm getting disk IO wait averages of
> ~70-90%. I've been tweaking the linux kernel as specified in the
> PostgreSQL documentations and switched to the deadline
> scheduler. Nothing seems to be fixing this. The queries are as
> optimized as I can get them. fsync is off in an attempt to help
> preformance still nothing. Are there any setting I should be look at
> the could improve on this???

Can you please characterize this a bit better?  Send the output of
vmstat or iostat over several minutes, or similar diagnostic
information.

Also please describe your hardware more.

Regards,
Jeff Baker