Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 13 Nov 2001 12:00:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 13 Nov 2001 12:00:24 -0500 Received: from ns2.cih.com ([204.69.206.3]:2433 "HELO cih.com") by vger.kernel.org with SMTP id ; Tue, 13 Nov 2001 12:00:15 -0500 Date: Tue, 13 Nov 2001 09:59:16 -0800 (PST) From: "Craig I. Hagan" To: Roy Sigurd Karlsbakk Cc: , Subject: Re: Tuning Linux for high-speed disk subsystems In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: MULTIPART/MIXED; BOUNDARY="1171030222-841085925-1005674337=:1083" Content-ID: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. Send mail to mime@docserver.cac.washington.edu for more info. --1171030222-841085925-1005674337=:1083 Content-Type: TEXT/PLAIN; CHARSET=US-ASCII Content-ID: > After some testing at Compaq's lab in Oslo, I've come to the conclusion > that Linux cannot scale higher than about 30-40MB/sec in or out of a > hardware or software RAID-0 set with several stripe/chunk sizes tried out. > The set is based on 5 18GB 10k disks running SCSI-3 (160MBps) alone on a > 32bit/33MHz PCI bus. this isn't quite true. use either the RH kernel, the -ac series, or the attached patch (for 2.4.15-pre4). Then set /proc/sys/vm/max-readahead to 511 or 1023 (power of 2 minus 1) this should allow you to generate large enough io's for streaming reads to do what you are looking for. -- craig ------------------------------------------------------------------------------- Craig I. Hagan "It's a small world, but I wouldn't want to back it up" hagan(at)cih.com "True hackers don't die, their ttl expires" "It takes a village to raise an idiot, but an idiot can raze a village" Stop the spread of spam, use a sendmail condom! http://www.cih.com/~hagan/smtpd-hacks In Bandwidth we trust --1171030222-841085925-1005674337=:1083 Content-Type: TEXT/PLAIN; CHARSET=US-ASCII; NAME="dynreadahead-2.4.15-pre4" Content-Transfer-Encoding: BASE64 Content-ID: Content-Description: Content-Disposition: ATTACHMENT; FILENAME="dynreadahead-2.4.15-pre4" ZGlmZiAtdXIgbGludXgtb3JpZy9kcml2ZXJzL21kL21kLmMgbGludXgvZHJp dmVycy9tZC9tZC5jDQotLS0gbGludXgtb3JpZy9kcml2ZXJzL21kL21kLmMJ TW9uIE5vdiAxMiAyMzozNDo1MiAyMDAxDQorKysgbGludXgvZHJpdmVycy9t ZC9tZC5jCU1vbiBOb3YgMTIgMjM6MzE6MTcgMjAwMQ0KQEAgLTMzOTgsNyAr MzM5OCw3IEBADQogCS8qDQogCSAqIFR1bmUgcmVjb25zdHJ1Y3Rpb246DQog CSAqLw0KLQl3aW5kb3cgPSBNQVhfUkVBREFIRUFEKihQQUdFX1NJWkUvNTEy KTsNCisJd2luZG93ID0gdm1fbWF4X3JlYWRhaGVhZCooUEFHRV9TSVpFLzUx 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