Message-ID: <4C0AD180.90607@2ndquadrant.com>
Date: Sat, 05 Jun 2010 18:36:48 -0400
From: Greg Smith <greg@2ndquadrant.com>
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To: Jon Schewe <jpschewe@mtu.net>
CC: pgsql-performance@postgresql.org
Subject: Re: How filesystems matter with PostgreSQL
References: <4C08EEDF.7090403@mtu.net>
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Jon Schewe wrote:
> The tests were all done on an opensuse 11.2 64-bit machine,
> on the same hard drive (just ran mkfs between each test) on the same
> input with the same code base.

So no controller card, just the motherboard and a single hard drive?  If 
that's the case, what you've measured is which filesystems are safe 
because they default to flushing drive cache (the ones that take around 
15 minutes) and which do not (the ones that take >=around 2 hours).  You 
can't make ext3 flush the cache correctly no matter what you do with 
barriers, they just don't work on ext3 the way PostgreSQL needs them to.

-- 
Greg Smith  2ndQuadrant US  Baltimore, MD
PostgreSQL Training, Services and Support
greg@2ndQuadrant.com   www.2ndQuadrant.us