Date: Wed, 20 Feb 2008 10:31:13 -0500
From: Michael Stone <mstone+postgres@mathom.us>
Subject: Re: Anyone using a SAN?
In-reply-to: <4544e0330802181344q2d98560du6bd4e481a9c9439f@mail.gmail.com>
To: Peter Koczan <pjkoczan@gmail.com>
Cc: pgsql-performance <pgsql-performance@postgresql.org>
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On Mon, Feb 18, 2008 at 03:44:40PM -0600, Peter Koczan wrote:
>One big reason we're really looking into a SAN option is that we have
>a lot of unused disk space.

The cost of the SAN interfaces probably exceeds the cost of the wasted
space, and the performance will probably be lower for a lot of 
workloads. There are good reasons to have SANs, but increasing 
utilization of disk drives probably isn't one of them.

>A typical disk usage scheme for us is 6 GB
>for a clean Linux install, and 20 GB for a Windows install. Our disks
>are typically 80GB, and even after decent amounts of usage we're not
>even approaching half that.

I typically partition systems to use a small fraction of the disk space, 
and don't even acknowledge that the rest exists unless there's an actual 
reason to use it. But the disks are basically free, so there's no point 
in trying to buy small ones to save space.

Mike Stone