From owner-freebsd-stable@FreeBSD.ORG Thu Jul 26 10:34:58 2007 Return-Path: Delivered-To: freebsd-stable@FreeBSD.ORG Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 77B9616A41A for ; Thu, 26 Jul 2007 10:34:58 +0000 (UTC) (envelope-from olli@lurza.secnetix.de) Received: from lurza.secnetix.de (lurza.secnetix.de [IPv6:2001:1b20:1:3::1]) by mx1.freebsd.org (Postfix) with ESMTP id CBE1813C48E for ; Thu, 26 Jul 2007 10:34:57 +0000 (UTC) (envelope-from olli@lurza.secnetix.de) Received: from lurza.secnetix.de (jqdovs@localhost [127.0.0.1]) by lurza.secnetix.de (8.13.4/8.13.4) with ESMTP id l6QAYnss001460; Thu, 26 Jul 2007 12:34:55 +0200 (CEST) (envelope-from oliver.fromme@secnetix.de) Received: (from olli@localhost) by lurza.secnetix.de (8.13.4/8.13.1/Submit) id l6QAYm7u001453; Thu, 26 Jul 2007 12:34:48 +0200 (CEST) (envelope-from olli) Date: Thu, 26 Jul 2007 12:34:48 +0200 (CEST) Message-Id: <200707261034.l6QAYm7u001453@lurza.secnetix.de> From: Oliver Fromme To: freebsd-stable@FreeBSD.ORG, scottl@samsco.org, hg@queue.to In-Reply-To: <46A7B7AF.6080308@samsco.org> X-Newsgroups: list.freebsd-stable User-Agent: tin/1.8.2-20060425 ("Shillay") (UNIX) (FreeBSD/4.11-STABLE (i386)) MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-2.1.2 (lurza.secnetix.de [127.0.0.1]); Thu, 26 Jul 2007 12:34:55 +0200 (CEST) Cc: Subject: Re: [resolved, ?naively] Re: geom vs ich through ar device - benchmarks? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: freebsd-stable@FreeBSD.ORG, scottl@samsco.org, hg@queue.to List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 26 Jul 2007 10:34:58 -0000 Scott Long wrote: > Howard Goldstein wrote: > > Naive test: dd if=/dev/zero of=/fsundertest/tstfile bs=1m count=1000 > > *not including buffered stuff unwritten, the test simply reported dd's > > idea of the transfer time*, and then the other way where it doesn't matter > > > > In firmware's RAID1 Using the awesome gmirror > > write 1gb: 13.275 13.7 > > rd 12.9 13.8 > > > > Of course after this I used gmirror... > > Just so we're clear, the ICH5 doesn't have any firmware and doesn't > actually do any RAID operations. What is has is hook into the system > BIOS during boot. That hook allows the BIOS to do RAID-like operations > during boot, until the OS takes over control of the devices. After > that, it's up to the OS to do all the RAID work. The 'ar' driver is > still software RAID, just like gmirror. What you've effectively done > merely compare the performance of one software RAID stack to another. > That's certainly an interesting comparison, but maybe not exactly what > you had in mind. As an additional note: _If_ the ICH RAID was in hardware (which it isn't, as Scott pointed out), it might be preferable to use it instead of gmirror, even if it's 5% slower, but because it would save a lot of cpu. Of course, since both are in software and probably consume similar amounts of cpu, it's better to use gmirror because it's a little faster. Best regards Oliver -- Oliver Fromme, secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing b. M. Handelsregister: Registergericht Muenchen, HRA 74606, Geschäftsfuehrung: secnetix Verwaltungsgesellsch. mbH, Handelsregister: Registergericht Mün- chen, HRB 125758, Geschäftsführer: Maik Bachmann, Olaf Erb, Ralf Gebhart FreeBSD-Dienstleistungen, -Produkte und mehr: http://www.secnetix.de/bsd "C++ is the only current language making COBOL look good." -- Bertrand Meyer