From: Andres Freund <andres@anarazel.de>
To: Tom Lane <tgl@sss.pgh.pa.us>
Subject: Re: How filesystems matter with PostgreSQL
Date: Fri, 4 Jun 2010 16:33:22 +0200
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Cc: pgsql-performance@postgresql.org,
 Jon Schewe <jpschewe@mtu.net>
References: <4C08EEDF.7090403@mtu.net> <201006041504.03218.andres@anarazel.de>
	<2503.1275661530@sss.pgh.pa.us>
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On Friday 04 June 2010 16:25:30 Tom Lane wrote:
> Andres Freund <andres@anarazel.de> writes:
> > On Friday 04 June 2010 14:17:35 Jon Schewe wrote:
> >> XFS (logbufs=8): ~4 hours to finish
> >> ext4: ~1 hour 50 minutes to finish
> >> ext3: 15 minutes to finish
> >> ext3 on LVM: 15 minutes to finish
> > 
> > My guess is that some of the difference comes from barrier differences.
> > ext4 uses barriers by default, ext3 does not.
> Or, to put it more clearly: the reason ext3 is fast is that it's unsafe.
Jon: To verify you can enable it via the barrier=1 option during mounting..

Andres