Received: from localhost (unknown [200.46.204.183]) by mail.postgresql.org (Postfix) with ESMTP id C9604650915 for ; Mon, 15 Dec 2008 14:09:28 -0400 (AST) Received: from mail.postgresql.org ([200.46.204.86]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 16563-01-7 for ; Mon, 15 Dec 2008 14:09:25 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from westnet.com (westnet.com [216.187.52.2]) by mail.postgresql.org (Postfix) with ESMTP id 88DB4650D2A for ; Mon, 15 Dec 2008 13:31:57 -0400 (AST) Received: from westnet.com (localhost [127.0.0.1]) by westnet.com (8.14.0/8.14.0) with ESMTP id mBFHVqKY021513; Mon, 15 Dec 2008 12:31:52 -0500 (EST) Received: from localhost (gsmith@localhost) by westnet.com (8.14.0/8.13.2/Submit) with ESMTP id mBFHVpFo021502; Mon, 15 Dec 2008 12:31:52 -0500 (EST) X-Authentication-Warning: westnet.com: gsmith owned process doing -bs Date: Mon, 15 Dec 2008 12:31:51 -0500 (EST) From: Greg Smith X-X-Sender: gsmith@westnet.com To: Adrian Moisey cc: pgsql-performance@postgresql.org Subject: Re: filesystems benchmark In-Reply-To: <4945FD58.8030604@careerjunction.co.za> Message-ID: References: <4945FD58.8030604@careerjunction.co.za> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0 tagged_above=0 required=5 tests=none X-Spam-Level: X-Archive-Number: 200812/156 X-Sequence-Number: 32192 On Mon, 15 Dec 2008, Adrian Moisey wrote: > I'm trying to compare different filesystems for postgres using pgbench. The > problem I've seen is that my IO wait is very very low. Is there a way I can > get pgbench to do more to push that up a little? Increase the database scale until the wait is what you expect. See http://www.westnet.com/~gsmith/gregsmith/content/postgresql/pgbench-scaling.htm for details. The latest filesystem performance comparison I'm aware of is at http://www.baconandtech.com/files/filesystem_io.pdf You might also take a look at that to make sure you're not re-mapping territory that's already been explored. -- * Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD