Received: from localhost (unknown [200.46.204.183]) by postgresql.org (Postfix) with ESMTP id AAD7264FCD7 for ; Fri, 8 Aug 2008 19:47:09 -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 01346-06 for ; Fri, 8 Aug 2008 19:47:01 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from westnet.com (westnet.com [216.187.52.2]) by postgresql.org (Postfix) with ESMTP id 75ADD64FCD6 for ; Fri, 8 Aug 2008 19:47:05 -0300 (ADT) Received: from westnet.com (localhost [127.0.0.1]) by westnet.com (8.14.0/8.14.0) with ESMTP id m78Ml3Fj026998; Fri, 8 Aug 2008 18:47:03 -0400 (EDT) Received: from localhost (gsmith@localhost) by westnet.com (8.14.0/8.13.2/Submit) with ESMTP id m78Ml38M026994; Fri, 8 Aug 2008 18:47:03 -0400 (EDT) X-Authentication-Warning: westnet.com: gsmith owned process doing -bs Date: Fri, 8 Aug 2008 18:47:03 -0400 (EDT) From: Greg Smith X-X-Sender: gsmith@westnet.com To: Henrik cc: pgsql-performance@postgresql.org Subject: Re: Filesystem benchmarking for pg 8.3.3 server In-Reply-To: <32A7A76B-16CA-4CDB-AD43-973AD6A3FC7B@mac.se> Message-ID: References: <32A7A76B-16CA-4CDB-AD43-973AD6A3FC7B@mac.se> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed 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: 200808/81 X-Sequence-Number: 30962 On Fri, 8 Aug 2008, Henrik wrote: > It feels like there is something fishy going on. Maybe the RAID 10 > implementation on the PERC/6e is crap? Normally, when a SATA implementation is running significantly faster than a SAS one, it's because there's some write cache in the SATA disks turned on (which they usually are unless you go out of your way to disable them). Since all non-battery backed caches need to get turned off for reliable database use, you might want to double-check that on the controller that's driving the SATA disks. -- * Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD