Received: from localhost (unknown [200.46.204.183]) by postgresql.org (Postfix) with ESMTP id 6C5BE64FCDD for ; Thu, 21 Aug 2008 02:50:53 -0300 (ADT) Received: from postgresql.org ([200.46.204.86]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 72028-04 for ; Thu, 21 Aug 2008 02:50:46 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from lists.commandprompt.com (host-159.commandprompt.net [207.173.203.159]) by postgresql.org (Postfix) with ESMTP id 3A8D864FCC9 for ; Thu, 21 Aug 2008 02:50:43 -0300 (ADT) Received: from [192.168.1.226] (or-69-34-217-90.sta.embarqhsd.net [69.34.217.90]) (authenticated bits=0) by lists.commandprompt.com (8.13.8/8.13.8) with ESMTP id m7L5rZkM007995 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 20 Aug 2008 22:53:39 -0700 Message-ID: <48AD022E.7090400@commandprompt.com> Date: Wed, 20 Aug 2008 22:50:38 -0700 From: "Joshua D. Drake" Organization: Command Prompt, Inc. User-Agent: Thunderbird 2.0.0.16 (Windows/20080708) MIME-Version: 1.0 To: Christiaan Willemsen CC: Merlin Moncure , pgsql-performance@postgresql.org Subject: Re: How to setup disk spindles for best performance References: <972BDF1A-B4ED-46EC-B416-0CDF15A0439A@technocon.com> <331B8FD1-7460-4B97-BD2C-03D8381E1C4D@technocon.com> In-Reply-To: <331B8FD1-7460-4B97-BD2C-03D8381E1C4D@technocon.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.0 (lists.commandprompt.com [207.173.203.159]); Wed, 20 Aug 2008 22:53:40 -0700 (PDT) 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: 200808/239 X-Sequence-Number: 31120 Christiaan Willemsen wrote: > So, what you are basically saying, is that a single mirror is in general > more than enough to facilitate the transaction log. http://www.commandprompt.com/blogs/joshua_drake/2008/04/is_that_performance_i_smell_ext2_vs_ext3_on_50_spindles_testing_for_postgresql/ http://wiki.postgresql.org/wiki/HP_ProLiant_DL380_G5_Tuning_Guide And to answer your question, yes. Transaction logs are written sequentially. You do not need a journaled file system and raid 1 is plenty for most if not all work loads. Sincerely, Joshua D. Drake