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Date: Wed, 13 Feb 2008 12:58:03 -0500
From: "Alex Deucher" <alexdeucher@gmail.com>
To: "Kenneth Marshall" <ktm@rice.edu>
Subject: Re: Anyone using a SAN?
Cc: "Peter Koczan" <pjkoczan@gmail.com>,
	pgsql-performance <pgsql-performance@postgresql.org>
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On Feb 13, 2008 12:46 PM, Kenneth Marshall <ktm@rice.edu> wrote:
> On Wed, Feb 13, 2008 at 10:56:54AM -0600, Peter Koczan wrote:
> > Hi all,
> >
> > We're considering setting up a SAN where I work. Is there anyone using
> > a SAN, for postgres or other purposes? If so I have a few questions
> > for you.
> >
> > - Are there any vendors to avoid or ones that are particularly good?
> >
> > - What performance or reliability implications exist when using SANs?
> >
> > - Are there any killer features with SANs compared to local storage?
> >
> > Any other comments are certainly welcome.
> >
> > Peter
> >
>
> Peter,
>
> The key is to understand your usage patterns, both I/O and query.
> SANs can be easily bandwidth limited which can tank your database
> performance. There have been several threads in the mailing list
> about performance problems caused by the use of a SAN for storage.

It's critical that you set up the SAN with a database in mind
otherwise the performance will be bad.  I tested a DB on a SAN
designed to maximize storage space and performance was terrible.  I
never had the time or resources to reconfigure the SAN to test a more
suitable spindle setup since the SAN was in heavy production use for
file archiving.

Alex