Received: from localhost (unknown [200.46.204.183]) by mail.postgresql.org (Postfix) with ESMTP id D890764FE93 for ; Wed, 10 Dec 2008 10:30:32 -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 39493-05 for ; Wed, 10 Dec 2008 10:30:30 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from mx.inode.at (mx16.lb01.inode.at [62.99.145.18]) by mail.postgresql.org (Postfix) with ESMTP id 1967A64FEA9 for ; Wed, 10 Dec 2008 10:30:30 -0400 (AST) Received: from [85.124.56.44] (port=7011 helo=[10.192.17.33]) by smartmx-16.inode.at with esmtp (Exim 4.50) id 1LAQ52-0003Rk-9f; Wed, 10 Dec 2008 15:30:24 +0100 Message-ID: <493FD27C.70704@sime.com> Date: Wed, 10 Dec 2008 15:30:20 +0100 From: Mario Weilguni User-Agent: Thunderbird 2.0.0.18 (X11/20081125) MIME-Version: 1.0 To: Scott Marlowe CC: Alan Hodgson , pgsql-performance@postgresql.org Subject: Re: Experience with HP Smart Array P400 and SATA drives? References: <4934FE60.30702@sime.com> <49395B57.EE98.0025.0@wicourts.gov> <200812051530.01258@hal.medialogik.com> <493E61E1.1020303@sime.com> <493F739C.9080800@sime.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed 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: 200812/116 X-Sequence-Number: 32152 Scott Marlowe schrieb: > On Wed, Dec 10, 2008 at 12:45 AM, Mario Weilguni wrote: > >> A customer of us uses the P400 on a different machine, 8 SAS drives (Raid 5 >> as well), and the performance is very, very good. So we thought it's a good >> choice. Maybe the SATA drives are the root of this problem? >> > > What tests have you or the customer done to confirm that performance > is very very good? A lot of times the system is not as fast as the > customer thinks, it's just faster than it was before and they're > happy. Also, there could be problems in the driver or firmware on > your P400 versus the customer one. I'd look for those differences as > well. I doubt SATA versus SAS is the problem, but who knows... > > Well, I cannot take the box offline to make usefull tests like tiobench or bonnie, but even with the current service running I get from a simple dd between 270 and 340 MB/sec sustained read over 30% of the disk. It also performed extremly good when I put the box into production, pg_bench values were impressing, but I do not have them at hand. However, currently we are seriously considering dropping RAID5 in favor of RAID10, we will test this week if this performs better. Regards Mario