Date: Fri, 15 Jul 2005 15:48:13 -0600
Message-ID: <871x5zbv1e.wl%ron@rwsoft.ca>
From: Ron Wills <ron@rwsoft.ca>
To: "Jeffrey W. Baker" <jwbaker@acm.org>
Cc: Ron Wills <ron@rwsoft.ca>, pgsql-performance@postgresql.org
Subject: Re: Really bad diskio
In-Reply-To: <1121462254.29379.3.camel@toonses.gghcwest.com>
References: <8764vbby7r.wl%ron@rwsoft.ca> <42D82053.1090309@commandprompt.com>
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	<1121462254.29379.3.camel@toonses.gghcwest.com>
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At Fri, 15 Jul 2005 14:17:34 -0700,
Jeffrey W. Baker wrote:
> 
> On Fri, 2005-07-15 at 15:04 -0600, Ron Wills wrote:
> > At Fri, 15 Jul 2005 13:45:07 -0700,
> > Joshua D. Drake wrote:
> > > 
> > > 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. 
> > > 
> > > 2 drives?
> > > 4 drives?
> > > 8 drives?
> > 
> >   3 drives raid 5. I don't believe it's the raid. I've tested this by
> > moving the database to the mirrors software raid where the root is
> > found and onto the the SATA raid. Neither relieved the IO problems.
> 
> Hard or soft RAID?  Which controller?  Many of the 3Ware controllers
> (85xx and 95xx) have extremely bad RAID 5 performance.
> 
> Did you take any pgbench or other benchmark figures before you started
> using the DB?

  No, unfortunatly, I'm more or less just the developer for the
automation systems and admin the system to keep everything going. I
have very little say in the hardware used and I don't have any
physical access to the machine, it's found a province over :P.
  But, for what the system, this IO seems unreasonable. I run
development on a 1.4Ghz Athlon, Gentoo system, with no raid and I
can't reproduce this kind of IO :(.

> -jwb