Date: Fri, 07 Sep 2007 06:04:49 -0400
From: Michael Stone <mstone+postgres@mathom.us>
Subject: Re: SAN vs Internal Disks
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On Fri, Sep 07, 2007 at 12:26:23AM -0400, Greg Smith wrote:
>consider is this:  your SAN starts having funky problems, and your 
>database is down because of it.  You call the vendor.  They find out 
>you're running CentOS instead of RHEL and say that's the cause of your 
>problem (even though it probably isn't).  How much will such a passing the 
>buck problem cost your company?  If it's a significant number, you'd be 
>foolish to run CentOS instead of the real RHEL.  Some SAN vendors can be 
>very, very picky about what they will support, and for most business 
>environments the RHEL subscription isn't so expensive that it's worth 
>wandering into an area where your support situation is fuzzy just to save 
>that money.

Correct. Far more sensible to skip the expensive SAN solution, not worry 
about having to play games, and save *even more* money. 

SANs have their place, but postgres storage generally isn't it; you'll 
get more bang/buck with DAS and very likely better absolute performance 
as well.  SANs make sense if you're doing a shared filesystem (don't 
even think about doing this with postgres), or if you're consolidating 
backups & DR (which doesn't work especially well with databases).

Mike Stone