From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932076AbWEFVOE (ORCPT ); Sat, 6 May 2006 17:14:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932075AbWEFVOE (ORCPT ); Sat, 6 May 2006 17:14:04 -0400 Received: from mail.crosswalkinc.com ([72.16.196.98]:60942 "EHLO coach.cozx.com") by vger.kernel.org with ESMTP id S932076AbWEFVOD (ORCPT ); Sat, 6 May 2006 17:14:03 -0400 Message-ID: <445D124E.2020404@cozx.com> Date: Sat, 06 May 2006 15:17:02 -0600 From: Dave Pitts Organization: Colorado Zephyrs User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.11) Gecko/20050729 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Avi Kivity Cc: linux-kernel@vger.kernel.org Subject: Re: How can I boost block I/O performance References: <445CE6ED.30703@cozx.com> <445CF9E4.3040202@argo.co.il> In-Reply-To: <445CF9E4.3040202@argo.co.il> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Avi Kivity wrote: > Dave Pitts wrote: > >> Hello all: >> >> I've been trying some hacks to boost disk I/O performance mostly by >> changing values >> in the /proc/sys/vm filesystem. A vmstat display shows bursty block >> out counts with >> fairly consistent interrupt counts: >> >> procs -----------memory---------- ---swap-- -----io---- --system-- >> ----cpu---- >> r b swpd free buff cache si so bi bo in cs us >> sy id wa >> 4 0 720 80252 1820 7077456 0 0 9 852 5 11 1 >> 14 84 0 > > [...] > >> 5 0 720 90364 1860 7067080 0 0 40 66956 17995 95384 >> 0 17 82 0 >> >> This test is running several NFS clients to a RAID disk storage >> array. I also see the >> same behavior when running SFTP transfers. What I'd like is a more >> even block >> out behavior (even at the expense of other apps as this is a file >> server not an app >> server). The values that I've been hacking are the >> dirty_writeback_centisecs, >> dirty_background_ratio, etc. Am I barking up the wrong tree? > > No iowait time, plenty of idle time: looks like you are network > bound. What time of network are you running? > Well, it's an 8 cpu system. Does the idle time reflect the idle time of all cpu's? The network is a Gigabit Ethernet. -- Dave Pitts PULLMAN: Travel and sleep in safety and comfort. dpitts@cozx.com My other RV IS a Pullman (Colorado Pine). http://www.cozx.com/~dpitts