X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (unknown [200.46.204.144]) by svr1.postgresql.org (Postfix) with ESMTP id 7FBC7529B4 for ; Mon, 8 Aug 2005 16:27:34 -0300 (ADT) Received: from svr1.postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 96590-04 for ; Mon, 8 Aug 2005 19:27:31 +0000 (GMT) Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by svr1.postgresql.org (Postfix) with ESMTP id 1B0995290F for ; Mon, 8 Aug 2005 16:27:26 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.13.1/8.13.1) with ESMTP id j78JRP9J008435; Mon, 8 Aug 2005 15:27:25 -0400 (EDT) To: Kari Lavikka Cc: pgsql-performance@postgresql.org Subject: Re: Finding bottleneck In-reply-to: References: <6EE64EF3AB31D5448D0007DD34EEB3417DD026@Herge.rcsinc.local> <29384.1123520200@sss.pgh.pa.us> Comments: In-reply-to Kari Lavikka message dated "Mon, 08 Aug 2005 20:54:38 +0300" Date: Mon, 08 Aug 2005 15:27:25 -0400 Message-ID: <8434.1123529245@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, hits=0.006 tagged_above=0 required=5 tests=AWL X-Spam-Level: X-Archive-Number: 200508/70 X-Sequence-Number: 13817 Kari Lavikka writes: > Disk configurations looks something like this: > sda: data (10 spindles, raid10) > sdb: xlog & clog (2 spindles, raid1) > sdc: os and other stuff That's definitely wrong. Put clog on the data disk. The entire point of giving xlog its own spindle is that you don't ever want the disk heads moving off the current xlog file. I'm not sure how much this is hurting you, given that clog is relatively low volume, but if you're going to go to the trouble of putting xlog on a separate spindle then it should be a completely dedicated spindle. regards, tom lane