Received: from localhost (unknown [200.46.204.184]) by postgresql.org (Postfix) with ESMTP id CA50E2E00AF for ; Fri, 29 Feb 2008 10:51:58 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.184]) (amavisd-maia, port 10024) with ESMTP id 47834-01 for ; Fri, 29 Feb 2008 10:51:44 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from smtp20.orange.fr (smtp20.orange.fr [80.12.242.26]) by postgresql.org (Postfix) with ESMTP id BA8112E00AD for ; Fri, 29 Feb 2008 10:51:48 -0400 (AST) Received: from me-wanadoo.net (localhost [127.0.0.1]) by mwinf2027.orange.fr (SMTP Server) with ESMTP id 2764E1C000E2 for ; Fri, 29 Feb 2008 15:51:46 +0100 (CET) Received: from axege.com (LNeuilly-152-22-82-133.w193-251.abo.wanadoo.fr [193.251.23.133]) by mwinf2027.orange.fr (SMTP Server) with ESMTP id 8BA2F1C000DA for ; Fri, 29 Feb 2008 15:51:45 +0100 (CET) X-ME-UUID: 20080229145145572.8BA2F1C000DA@mwinf2027.orange.fr Received: from localhost (localhost [127.0.0.1]) by axege.com (Postfix) with ESMTP id C6DE04FE27 for ; Fri, 29 Feb 2008 17:02:14 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at myhostname="axege.com." Received: from axege.com ([127.0.0.1]) by localhost (axege.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 101FtwhemPeT for ; Fri, 29 Feb 2008 17:02:14 +0100 (CET) Received: from [10.0.0.69] (unknown [192.168.1.1]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by axege.com (Postfix) with ESMTP id 450E34FE26 for ; Fri, 29 Feb 2008 17:02:14 +0100 (CET) Subject: Re: 12 disks raid setup From: Franck Routier To: pgsql-performance In-Reply-To: References: <1204285894.11773.33.camel@franck-gusty> Content-Type: text/plain Organization: =?ISO-8859-1?Q?Ax=E8ge?= Sarl Date: Fri, 29 Feb 2008 15:51:45 +0100 Message-Id: <1204296705.11773.51.camel@franck-gusty> Mime-Version: 1.0 X-Mailer: Evolution 2.12.1 Content-Transfer-Encoding: 7bit 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: 200802/400 X-Sequence-Number: 28942 Hi, my Raid controller is an Adaptec 31205 SAS/RAID controller. The battery was an option, but I didn't know it at purchase time. So I have no battery, but the whole system is on an UPS. I have done quite a few tests using bonnie++, focusing on 'random seek' results, and found out that: 1) linux md raid 10 performs better than Adaptec hardware raid in this field (random seek) by 15%, quite consistently 2) hardware raid is better on sequential output 3) md outperforms it again when coming to sequential read, especially with far layout option. So in fact I think I will use md raid, but still don't know with which layout (3x4 or 1x12). What would you suggest as a benchmarking method ? Simply issue a few big queries that I expect to be usual and see how long it last, or is there a more convinient and or "scientific" method ? Thanks, Franck