Received: from maia.hub.org (maia-3.hub.org [200.46.204.243]) by mail.postgresql.org (Postfix) with ESMTP id 901566326E4 for ; Fri, 18 Jun 2010 01:20:03 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.243]) (amavisd-maia, port 10024) with ESMTP id 22885-10 for ; Fri, 18 Jun 2010 04:19:56 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from mail.catalyst.net.nz (bertrand.catalyst.net.nz [202.78.240.40]) by mail.postgresql.org (Postfix) with ESMTP id A14A0632239 for ; Fri, 18 Jun 2010 01:19:56 -0300 (ADT) Received: from localhost (localhost [127.0.0.1]) by mail.catalyst.net.nz (Postfix) with ESMTP id 67F4268498 for ; Fri, 18 Jun 2010 16:19:54 +1200 (NZST) X-Virus-Scanned: Debian amavisd-new at catalyst.net.nz Received: from mail.catalyst.net.nz ([127.0.0.1]) by localhost (bertrand.catalyst.net.nz [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 3p4K-qO2YIIa for ; Fri, 18 Jun 2010 16:19:53 +1200 (NZST) Received: from [192.168.1.11] (122-58-208-29.jetstream.xtra.co.nz [122.58.208.29]) (Authenticated sender: mark.kirkwood) by mail.catalyst.net.nz (Postfix) with ESMTPSA id A42CF339C5 for ; Fri, 18 Jun 2010 16:19:53 +1200 (NZST) Message-ID: <4C1AF3E8.4030608@catalyst.net.nz> Date: Fri, 18 Jun 2010 16:19:52 +1200 From: Mark Kirkwood User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.9) Gecko/20100423 Thunderbird/3.0.4 MIME-Version: 1.0 To: pgsql-performance@postgresql.org Subject: Re: wal_synch_method = open_sync safe on RHEL 5.5? References: <4C1ACE5F.1080802@catalyst.net.nz> <4C1AE820.6020506@2ndquadrant.com> In-Reply-To: <4C1AE820.6020506@2ndquadrant.com> 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=0.79 tagged_above=-10 required=5 tests=BAYES_50=0.8, T_RP_MATCHES_RCVD=-0.01 X-Spam-Level: X-Archive-Number: 201006/328 X-Sequence-Number: 39184 On 18/06/10 15:29, Greg Smith wrote: > > P.S. Be wary of expecting pgbench to give you useful numbers on a > single run. For the default write-heavy test, I recommend three runs > of 10 minutes each (-T 600 on recent PostgreSQL versions) before I > trust any results it gives. You can get useful data from the > select-only test in only a few seconds, but not the one that writes a > bunch. > Yeah, I did several runs of each, and a couple with -c 128 and -t 100000 to give the setup a good workout (also 2000-2400 tps, nice to see a well behaved SAN). Cheers Mark