Date: Tue, 1 Aug 2006 20:42:23 -0400
From: Alvaro Herrera <alvherre@commandprompt.com>
To: "J. Andrew Rogers" <jrogers@neopolitan.com>
Cc: Milen Kulev <makulev@gmx.net>,
	"Pgsql-Performance ((E-mail))" <pgsql-performance@postgresql.org>
Subject: Re: XFS filessystem for Datawarehousing
Message-ID: <20060802004223.GE20401@alvh.no-ip.org>
Mail-Followup-To: "J. Andrew Rogers" <jrogers@neopolitan.com>,
	Milen Kulev <makulev@gmx.net>,
	"Pgsql-Performance ((E-mail))" <pgsql-performance@postgresql.org>
References: <012d01c6b5b4$6db33680$0a00a8c0@trivadis.com>
	<D986D872-2CE4-4D12-B368-2F4494CFE08B@neopolitan.com>
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J. Andrew Rogers wrote:
> 
> On Aug 1, 2006, at 2:49 PM, Milen Kulev wrote:
> >Is anyone using XFS for storing/retrieving relatively large amount  
> >of data  (~ 200GB)?
> 
> 
> Yes, we've been using it on Linux since v2.4 (currently v2.6) and it  
> has been rock solid on our database servers (Opterons, running in  
> both 32-bit and 64-bit mode).  Our databases are not quite 200GB  
> (maybe 75GB for a big one currently), but ballpark enough that the  
> experience is probably valid.  We also have a few terabyte+ non- 
> database XFS file servers too.
> 
> Performance has been very good even with nearly full file systems,  
> and reliability has been perfect so far. Some of those file systems  
> get used pretty hard for months or years non-stop.  Comparatively, I  
> can only tell you that XFS tends to be significantly faster than  
> Ext3, but we never did any serious file system tuning either.

Most likely ext3 was used on the default configuration, which logs data
operations as well as metadata, which is what XFS logs.  I don't think
I've seen any credible comparison between XFS and ext3 with the
metadata-only journal option.

On the other hand I don't think it makes sense to journal data on a
PostgreSQL environment.  Metadata is enough, given that we log data on
WAL anyway.

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support