Message-ID: <4CD469EC.4090702@agliodbs.com>
Date: Fri, 05 Nov 2010 13:32:44 -0700
From: Josh Berkus <josh@agliodbs.com>
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To: Scott Marlowe <scott.marlowe@gmail.com>
CC: pgsql-performance@postgresql.org
Subject: Re: Major Linux performance regression; shouldn't we be
	worried about RHEL6?
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> Why would it be off limits?  Is it likely to lose data due to power failure etc?

If fsyncs are taking 5X as long, people can't use PostgreSQL on that
platform.

> Are you referring to improvements due to write barrier support getting
> fixed up fr ext4 to run faster but still be safe?  I would assume that
> any major patches that increase performance with write barriers
> without being dangerous for your data would get back ported by RH as
> usual.

Hopefully, yes.  I wouldn't mind confirmation of this, though; it
wouldn't be the first time RH shipped with known-bad IO performance.

-- 
                                  -- Josh Berkus
                                     PostgreSQL Experts Inc.
                                     http://www.pgexperts.com