Received: from localhost (unknown [200.46.204.183]) by postgresql.org (Postfix) with ESMTP id E714F64FCC2 for ; Thu, 21 Aug 2008 05:41:14 -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 21149-07 for ; Thu, 21 Aug 2008 05:41:08 -0300 (ADT) X-Greylist: delayed 00:06:04.376464 by SQLgrey-1.7.6 Received: from amidala.server.telavista.net (amidala.server.telavista.net [213.239.138.194]) by postgresql.org (Postfix) with ESMTP id EF17564FCE6 for ; Thu, 21 Aug 2008 05:41:10 -0300 (ADT) Received: from firewall.tecnocon.com (gateway.technocon.com [62.132.195.8]) by amidala.server.telavista.net (Postfix) with ESMTP id 3595B6D4053; Thu, 21 Aug 2008 10:34:56 +0200 (CEST) Received: from [192.168.0.129] (unknown [192.168.0.129]) by firewall.tecnocon.com (Postfix) with ESMTP id 13C55225212; Thu, 21 Aug 2008 10:34:57 +0200 (CEST) Message-ID: <48AD288B.8030902@technocon.com> Date: Thu, 21 Aug 2008 10:34:19 +0200 From: Christiaan Willemsen User-Agent: Thunderbird 2.0.0.16 (Windows/20080708) MIME-Version: 1.0 To: "Joshua D. Drake" 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> <48AD022E.7090400@commandprompt.com> In-Reply-To: <48AD022E.7090400@commandprompt.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-svmilter: 3595B6D4053: result=CLEAN, action=ACCEPT, virus=-1, spam=-1, rbl=0, nbl=0, pbl=0 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: 200808/245 X-Sequence-Number: 31126 Thanks Joshua, So what about putting the indexes on a separate array? Since we do a lot of inserts indexes are going to be worked on a lot of the time. Regards, Christiaan Joshua D. Drake wrote: > 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 >