Received: from localhost (unknown [200.46.204.183]) by postgresql.org (Postfix) with ESMTP id 08B2B64FCD2 for ; Wed, 10 Sep 2008 03:53:22 -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 84259-03 for ; Wed, 10 Sep 2008 03:53:19 -0300 (ADT) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from nf-out-0910.google.com (nf-out-0910.google.com [64.233.182.191]) by postgresql.org (Postfix) with ESMTP id 0217764FCCB for ; Wed, 10 Sep 2008 03:53:18 -0300 (ADT) Received: by nf-out-0910.google.com with SMTP id c7so889639nfi.23 for ; Tue, 09 Sep 2008 23:53:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to :subject:cc:mime-version:content-type:content-transfer-encoding :content-disposition; bh=xNG0loqaGhkZuQaesZIOomPE959MCiY1QkvviIRKd0o=; b=j0W1ezUWazIuS9T0CmuVecHNdXMAF+rwxYBTf2DcX2NWHaKEeJR8YX0qOIFEW9Iqbl QiZLXSullpCLiuZ+edaQRT9eJCfHmyergX+lHT2kj8DCEmSnuxpB+LmARhl3bds6/dZY GKtYszGZuYCOOixVVMjQhDvrXzR4GsXhj8cTw= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:mime-version:content-type :content-transfer-encoding:content-disposition; b=on9b+0lPu8X6LgV0fgyMSexUId4gfE0iu1+fKhIeJrbjmaqIrbcSMJiHSA+LoUxKQA OqNsjC+Nj5nyXzPwET//gSS2COCMxAuTnZY9vlCWVDV1UMSZAn0f1kqu1PNvpzklJFEh QCAghwSblqyQzu7sxZU+MFZNnUAPKoRyocIB4= Received: by 10.210.71.13 with SMTP id t13mr965651eba.112.1221029597459; Tue, 09 Sep 2008 23:53:17 -0700 (PDT) Received: by 10.210.34.14 with HTTP; Tue, 9 Sep 2008 23:53:17 -0700 (PDT) Message-ID: <70c01d1d0809092353r4ae687a3ycf3d99d43a5680cf@mail.gmail.com> Date: Tue, 9 Sep 2008 23:53:17 -0700 From: "Mark Wong" To: "pgsql-performance@postgresql.org" Subject: Effects of setting linux block device readahead size Cc: "Gabrielle Roth" , "Selena Deckelmann" MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline 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: 200809/103 X-Sequence-Number: 31416 Hi all, I've started to display the effects of changing the Linux block device readahead buffer to the sequential read performance using fio. There are lots of raw data buried in the page, but this is what I've distilled thus far. Please have a look and let me know what you think: http://wiki.postgresql.org/wiki/HP_ProLiant_DL380_G5_Tuning_Guide#Readahead_Buffer_Size Regards, Mark