Received: from localhost (unknown [200.46.204.183]) by mail.postgresql.org (Postfix) with ESMTP id 01D4F633E7A for ; Fri, 10 Apr 2009 14:31:46 -0300 (ADT) 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 03822-01 for ; Fri, 10 Apr 2009 14:31:42 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from outmail129151.authsmtp.co.uk (outmail129151.authsmtp.co.uk [62.13.129.151]) by mail.postgresql.org (Postfix) with ESMTP id 34711633A76 for ; Fri, 10 Apr 2009 14:31:42 -0300 (ADT) Received: from mail-c188.authsmtp.com (mail-c188.authsmtp.com [62.13.128.25]) by punt8.authsmtp.com (8.14.2/8.14.2/Kp) with ESMTP id n3AHVcuM084614; Fri, 10 Apr 2009 18:31:38 +0100 (BST) Received: from Sidney-Stratton.local (adsl-63-195-55-98.dsl.snfc21.pacbell.net [63.195.55.98]) (authenticated bits=0) by mail.authsmtp.com (8.14.2/8.14.2/Kp) with ESMTP id n3AHVZJi090144; Fri, 10 Apr 2009 18:31:36 +0100 (BST) Message-ID: <49DF8277.4050801@agliodbs.com> Date: Fri, 10 Apr 2009 10:31:35 -0700 From: Josh Berkus Organization: PostgreSQL Experts Inc. User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.1b3pre) Gecko/20090223 Thunderbird/3.0b2 MIME-Version: 1.0 To: Scott Carey CC: henk de wit , jesper@krogh.cc, pgsql-performance@postgresql.org Subject: Re: Using IOZone to simulate DB access patterns References: In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Server-Quench: 722fd770-25f5-11de-aecc-001871e930f4 X-AuthRoute: OCdyZgscClZXSx8a IioLCC5HRQ8+YBZL BAkGMA9GIUINWEQN c1ADdh16KEdbHwkB CnYKU15XUVdyUS1z aBRQZABDZ09QVg11 Uk1LR01SWltrcGRn bGRHUhBydgFCNn9x YE4sWXJZChB9ckZg QEsCEHAHZDM1dTFK AxNFdwNVeARLKxZG agZ7GhFYa3VsBg8C MSgJGgV5AC5eLisd YyY/KlQfCVoMViU9 Qg0GFCkiVWEvDyw4 JBE9MRYEFVoNP180 KjNh X-Authentic-SMTP: 61633136333939.cat.dmpriest.net.uk:1378/Kp X-Report-SPAM: If SPAM / abuse - report it at: http://www.authsmtp.com/abuse X-Virus-Status: No virus detected - but ensure you scan with your own anti-virus system. 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: 200904/200 X-Sequence-Number: 33567 Scott, > FIO with profiles such as the below samples are easy to set up, and they can > be mix/matched to test what happens with mixed read/write seq/rand -- with > surprising and useful tuning results. Forcing a cache flush or sync before > or after a run is trivial. Changing to asynchronous I/O, direct I/O, or > other forms is trivial. The output result formatting is very useful as > well. FIO? Link? -- Josh Berkus PostgreSQL Experts Inc. www.pgexperts.com