Received: from maia.hub.org (unknown [200.46.208.211]) by mail.postgresql.org (Postfix) with ESMTP id F0AB0632A5D for ; Tue, 9 Feb 2010 12:23:10 -0400 (AST) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.208.211]) (amavisd-maia, port 10024) with ESMTP id 18066-10 for ; Tue, 9 Feb 2010 16:23:00 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from shrek.krogh.cc (2605ds1-ynoe.0.fullrate.dk [90.184.12.24]) by mail.postgresql.org (Postfix) with ESMTP id 25D7F636B3D for ; Tue, 9 Feb 2010 12:22:59 -0400 (AST) Received: from localhost (localhost [127.0.0.1]) by shrek.krogh.cc (Postfix) with ESMTP id CBC531F98F7; Tue, 9 Feb 2010 17:22:56 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at shrek.krogh.cc Received: from shrek.krogh.cc ([127.0.0.1]) by localhost (shrek.krogh.cc [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id bY+OE28MS65M; Tue, 9 Feb 2010 17:22:52 +0100 (CET) Received: from [90.184.13.137] (unknown [90.184.13.137]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: jesper@krogh.cc) by shrek.krogh.cc (Postfix) with ESMTPSA id 8D5B11F9675; Tue, 9 Feb 2010 17:22:52 +0100 (CET) Message-ID: <4B718BDB.8080807@krogh.cc> Date: Tue, 09 Feb 2010 17:22:51 +0100 From: Jesper Krogh User-Agent: Thunderbird 2.0.0.23 (X11/20090817) MIME-Version: 1.0 To: Kevin Grittner CC: pgsql-performance@postgresql.org Subject: Re: moving pg_xlog -- yeah, it's worth it! References: <4B71358E020000250002F0E4@gw.wicourts.gov> In-Reply-To: <4B71358E020000250002F0E4@gw.wicourts.gov> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-2.028 tagged_above=-10 required=5 tests=AWL=0.571, BAYES_00=-2.599 X-Spam-Level: X-Archive-Number: 201002/137 X-Sequence-Number: 37558 > > Frankly, I was quite surprised by this, since some of the benchmarks > people have published on the effects of using a separate RAID for > the WAL files have only shown a one or two percent difference when > using a hardware RAID controller with BBU cache configured for > write-back. Hi Kevin. Nice report, but just a few questions. Sorry if it is obvious.. but what filesystem/OS are you using and do you have BBU-writeback on the main data catalog also? Jesper