Received: from localhost (maia-3.hub.org [200.46.204.184]) by postgresql.org (Postfix) with ESMTP id 7F5509FA252 for ; Fri, 1 Dec 2006 10:29:14 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.184]) (amavisd-new, port 10024) with ESMTP id 73342-02-2 for ; Fri, 1 Dec 2006 10:28:59 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey-1.7.4 Received: from server.linux27.com (server.linux27.com [72.232.77.42]) by postgresql.org (Postfix) with ESMTP id 2AB069FA178 for ; Fri, 1 Dec 2006 10:29:04 -0400 (AST) Received: from [201.67.231.52] (port=10245 helo=PC1) by server.linux27.com with esmtpa (Exim 4.52) id 1Gq9Nu-0001lC-Fm; Fri, 01 Dec 2006 12:29:02 -0200 Reply-To: From: "Carlos H. Reimer" To: Cc: Subject: RES: Bad iostat numbers Date: Fri, 1 Dec 2006 12:29:11 -0200 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0) In-Reply-To: <456F9262.4080207@boreham.org> Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2962 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - server.linux27.com X-AntiAbuse: Original Domain - postgresql.org X-AntiAbuse: Originator/Caller UID/GID - [0 0] / [47 12] X-AntiAbuse: Sender Address Domain - opendb.com.br X-Source: X-Source-Args: X-Source-Dir: X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200612/4 X-Sequence-Number: 22060 Hi, I´ve taken a look in the /var/log/messages and found some temperature messages about the disk drives: Nov 30 11:08:07 totall smartd[1620]: Device: /dev/sda, Temperature changed 2 Celsius to 51 Celsius since last report Can this temperature influence in the performance? Reimer > -----Mensagem original----- > De: David Boreham [mailto:david_list@boreham.org] > Enviada em: sexta-feira, 1 de dezembro de 2006 00:25 > Para: carlos.reimer@opendb.com.br > Cc: pgsql-performance@postgresql.org > Assunto: Re: [PERFORM] Bad iostat numbers > > > Carlos H. Reimer wrote: > > > > > > > avg-cpu: %user %nice %system %iowait %idle > > > > 50.40 0.00 0.50 1.10 48.00 > > > > > > > > Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s > > avgrq-sz avgqu-sz await svctm %util > > > > sda 0.00 7.80 0.40 6.40 41.60 113.60 20.80 > > 56.80 22.82 570697.50 10.59 147.06 100.00 > > > > sdb 0.20 7.80 0.60 6.40 40.00 113.60 20.00 > > 56.80 21.94 570697.50 9.83 142.86 100.00 > > > > md1 0.00 0.00 1.20 13.40 81.60 107.20 40.80 > > 53.60 12.93 0.00 0.00 0.00 0.00 > > > > md0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 > > 0.00 0.00 0.00 0.00 0.00 0.00 > > > > > > > > Are they not saturated? > > > > > > > > What kind of parameters should I pay attention when comparing SCSI > > controllers and disks? I would like to discover how much cache is > > present in the controller, how can I find this value from Linux? > > > > > These number look a bit strange. I am wondering if there is a hardware > problem on one of the drives > or on the controller. Check in syslog for messages about disk timeouts > etc. 100% util but 6 writes/s > is just wrong (unless the drive is a 1980's vintage floppy). > > > >