Message-ID: <4BE852CE.9020802@agliodbs.com>
Date: Mon, 10 May 2010 11:39:10 -0700
From: Josh Berkus <josh@agliodbs.com>
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To: postgres performance list <pgsql-performance@postgresql.org>
Subject: Re: 8K recordsize bad on ZFS?
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On 5/9/10 1:45 AM, Dimitri wrote:
> Josh,
> 
> it'll be great if you explain how did you change the records size to
> 128K? - as this size is assigned on the file creation and cannot be
> changed later - I suppose that you made a backup of your data and then
> process a full restore.. is it so?

You can change the recordsize of the zpool dynamically, then simply copy
the data directory (with PostgreSQL shut down) to a new directory on
that zpool.  This assumes that you have enough space on the zpool, of
course.

We didn't test how it would work to let the files in the Postgres
instance get gradually replaced by "natural" updating.

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