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Subject: Re: strange performance regression between 7.4 and 8.1
From: Scott Marlowe <smarlowe@g2switchworks.com>
To: Alex Deucher <alexdeucher@gmail.com>
Cc: Ron <rjpeace@earthlink.net>, pgsql-performance@postgresql.org
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On Fri, 2007-03-02 at 10:03, Alex Deucher wrote:
> On 3/2/07, Ron <rjpeace@earthlink.net> wrote:
> > At 10:16 AM 3/2/2007, Alex Deucher wrote:

> > d=  you went from local HD IO to a SAN
> > (many differences hidden in that one line...  ...and is the physical
> > layout of tables and things like pg_xlog sane on the SAN?)
> >
> >
> > ...and you did this by just pulling over the old DB onto the new HW?
> >
> 
> We rebuild the DB from scratch on the new server.  Same table
> structure though.  We reloaded from the source material directly.

I would REALLY recommend testing this machine out with a simple software
RAID-1 pair of SCSI or SATA drives just to eliminate or confirm the SAN
as the root problem.