Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932473AbVKMMAJ (ORCPT ); Sun, 13 Nov 2005 07:00:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932475AbVKMMAJ (ORCPT ); Sun, 13 Nov 2005 07:00:09 -0500 Received: from mailhost.u-strasbg.fr ([130.79.200.152]:57807 "EHLO mailhost.u-strasbg.fr") by vger.kernel.org with ESMTP id S932473AbVKMMAH (ORCPT ); Sun, 13 Nov 2005 07:00:07 -0500 Message-ID: <43772A54.3090904@crc.u-strasbg.fr> Date: Sun, 13 Nov 2005 12:58:12 +0100 From: Philippe Pegon User-Agent: Mozilla Thunderbird 1.0.7 (X11/20051016) X-Accept-Language: en-us, en MIME-Version: 1.0 To: "Miro Dietiker, MD Systems" CC: "'Neil Brown'" , linux-kernel@vger.kernel.org Subject: Re: AW: Locking md device and system for several seconds References: <018a01c5e844$18127490$4001a8c0@MDSYSPORT> In-Reply-To: <018a01c5e844$18127490$4001a8c0@MDSYSPORT> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-2.0 (mailhost.u-strasbg.fr [IPv6:2001:660:2402::152]); Sun, 13 Nov 2005 12:59:52 +0100 (CET) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1837 Lines: 55 Miro Dietiker, MD Systems wrote: > :-) > > >>Can you check which IO scheduler the drives are using, try different >>schedulers, and see if it makes a different. > > > there was [anticipatory] selected. > > ORIGINAL: > tiger:~# grep . /sys/block/*/queue/scheduler > /sys/block/fd0/queue/scheduler:noop [anticipatory] deadline cfq > /sys/block/hdd/queue/scheduler:noop [anticipatory] deadline cfq > /sys/block/sda/queue/scheduler:noop [anticipatory] deadline cfq > /sys/block/sdb/queue/scheduler:noop [anticipatory] deadline cfq > > NEW: > tiger:~# grep . /sys/block/*/queue/scheduler > /sys/block/fd0/queue/scheduler:noop anticipatory deadline [cfq] > /sys/block/hdd/queue/scheduler:noop anticipatory deadline [cfq] > /sys/block/sda/queue/scheduler:noop anticipatory deadline [cfq] > /sys/block/sdb/queue/scheduler:noop anticipatory deadline [cfq] > > System seems to work, but I need some testing time to check that > behaviour. (Any suggestion of a testing tool to generate disk > traffic and reporting response-times and throughput?) > > Which is the right way / position on bootup to set this field > permanent to this value and what exactly did I change with this > modification? (Performance issues?) > I'm using debian.. you can use the kernel argument elevator=cfq in your lilo or grub boot config file. you can read this article about cfq : http://lwn.net/Articles/143474/ for information, it seems cfq is used in the default kernel in some distributions. > > I also need to check this on the other (identical) machines. > > Thanks! Miro Dietiker -- Philippe Pegon - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/