Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751034AbWEFSJF (ORCPT ); Sat, 6 May 2006 14:09:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751057AbWEFSJE (ORCPT ); Sat, 6 May 2006 14:09:04 -0400 Received: from mail.crosswalkinc.com ([72.16.196.98]:61446 "EHLO coach.cozx.com") by vger.kernel.org with ESMTP id S1751034AbWEFSJE (ORCPT ); Sat, 6 May 2006 14:09:04 -0400 Message-ID: <445CE6ED.30703@cozx.com> Date: Sat, 06 May 2006 12:11:57 -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: linux-kernel@vger.kernel.org Subject: How can I boost block I/O performance 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 Content-Length: 2859 Lines: 75 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 1 0 720 80444 1820 7077456 0 0 0 0 15923 77712 4 20 76 0 2 0 720 80196 1820 7077524 0 0 0 0 14705 87207 4 18 79 0 2 0 720 79732 1828 7077856 0 0 8 116 16235 84459 4 20 76 0 4 0 720 104172 1812 7051964 0 0 24 62568 20447 73499 4 27 69 0 2 0 720 105172 1812 7051964 0 0 0 90740 16960 80149 1 21 78 0 2 0 720 104108 1812 7051964 0 0 0 0 14162 72632 3 13 85 0 4 0 720 103980 1812 7052032 0 0 0 0 13495 68133 4 16 80 0 1 0 720 103868 1820 7052704 0 0 0 128 15417 59969 4 17 79 0 0 0 720 104340 1828 7052696 0 0 0 280 19504 74281 0 8 92 0 0 0 720 104532 1828 7052696 0 0 0 0 14736 70017 0 5 95 0 1 0 720 104596 1828 7052696 0 0 0 0 16006 73173 0 6 94 0 2 0 720 92844 1828 7064256 0 0 12 0 16508 80601 0 9 91 0 2 0 720 91916 1836 7064248 0 0 4 104 20787 74676 0 7 92 0 0 0 720 92580 1844 7064240 0 0 0 14640 17789 71545 0 10 90 0 1 0 720 92900 1844 7064240 0 0 0 0 15460 74760 0 8 92 0 0 0 720 92668 1844 7065260 0 0 0 0 18585 77435 0 7 93 0 0 0 720 92604 1844 7065260 0 0 0 0 19187 86426 0 9 91 0 2 0 720 91964 1860 7065244 0 0 0 140 23659 87962 0 8 92 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? Thanks in advance. -- 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 - 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/