Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261177AbVAMG6q (ORCPT ); Thu, 13 Jan 2005 01:58:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261179AbVAMG6q (ORCPT ); Thu, 13 Jan 2005 01:58:46 -0500 Received: from h-66-134-203-88.snvacaid.covad.net ([66.134.203.88]:54073 "EHLO mail.zanfx.com") by vger.kernel.org with ESMTP id S261177AbVAMG6o (ORCPT ); Thu, 13 Jan 2005 01:58:44 -0500 Message-ID: <41E61C68.10801@zanfx.com> Date: Wed, 12 Jan 2005 22:59:52 -0800 From: "Paul A. Sumner" User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040622 X-Accept-Language: en-us, en MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: Re: High write latency, iowait, slow writes 2.6.9 References: <41E4BB99.90908@zanfx.com> In-Reply-To: X-Enigmail-Version: 0.83.3.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1547 Lines: 47 Thanks... I've tried the as, deadline and cfq schedulers. Deadline is giving me the best results. I've also tried tweaking the stuff in /sys/block/sda/queue/iosched/. For lack of a better way of describing it, it seems like something is thrashing. Miquel van Smoorenburg wrote: > In article <41E4BB99.90908@zanfx.com>, > Paul A. Sumner wrote: > >>I have a new server that during big io tasks, e.g., bonnie++ and >>tiobench testing, becomes very unresponsive. Both bonnie++ and tiobench >>show good read performance, but the write performance lags, max >>latencies are into the *minutes* and it experiences extended high >>iowait. I'm guessing the iowait may not be a real problem. The machine >>is as follows: > > > Try another IO scheduler (boot with elevator=deadline or elevator=cfq > on the kernel command line) > > Mike. > > - > 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/ -- Paul A. Sumner Principal Software Engineer Moore Iacofano Goltsman, Inc. (MIG) 800 Hearst Avenue Berkeley, CA 94710 Office: 510-845-7549 ext. 191 FAX: 510-845-8750 Mobile: 510-812-1520 - 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/