Received: from maia.hub.org (maia-2.hub.org [200.46.204.251]) by mail.postgresql.org (Postfix) with ESMTP id 0A7FCB5DCB7 for ; Mon, 5 Sep 2011 14:24:33 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.251]) (amavisd-maia, port 10024) with ESMTP id 75082-04 for ; Mon, 5 Sep 2011 17:24:27 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from mail.anarazel.de (mail.anarazel.de [217.115.131.40]) by mail.postgresql.org (Postfix) with ESMTP id C20DCB5DCA8 for ; Mon, 5 Sep 2011 14:24:26 -0300 (ADT) Received: from intern.anarazel.de (p57A9EDDB.dip.t-dialin.net [87.169.237.219]) (Authenticated sender: andres@anarazel.de) by mail.anarazel.de (Postfix) with ESMTPA id 975AE448006; Mon, 5 Sep 2011 19:24:20 +0200 (CEST) From: Andres Freund To: pgsql-performance@postgresql.org Cc: Richard Shaw , Andy Colson Subject: Re: Rather large LA Date: Mon, 05 Sep 2011 19:24:17 +0200 Message-ID: <1894838.pasMZSmQAq@alap2> User-Agent: KMail/4.7.0 (Linux/3.0.1-andres; KDE/4.7.0; x86_64; ; ) In-Reply-To: <97BCA6CA-A1DB-43C7-B710-C2836B656FD6@aggress.net> References: <4E64D0FE.6020704@squeakycode.net> <97BCA6CA-A1DB-43C7-B710-C2836B656FD6@aggress.net> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-2.404 tagged_above=-10 required=5 tests=BAYES_00=-1.9, RP_MATCHES_RCVD=-0.504 X-Spam-Level: X-Archive-Number: 201109/45 X-Sequence-Number: 44821 On Monday, September 05, 2011 14:57:43 Richard Shaw wrote: > Autovacuum has been disabled and set to run manually via cron during a quiet > period and fsync has recently been turned off to gauge any real world > performance increase, there is battery backup on the raid card providing > some level of resilience. That doesn't help you against a failure due to fsync() off as the BBU can only protect data that actually has been written to disk. Without fsync=on no guarantee about that exists. Andres