From owner-freebsd-current@FreeBSD.ORG Wed Mar 30 20:03:36 2005 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 2CA2916A4CE for ; Wed, 30 Mar 2005 20:03:36 +0000 (GMT) Received: from mxfep02.bredband.com (mxfep02.bredband.com [195.54.107.73]) by mx1.FreeBSD.org (Postfix) with ESMTP id 5D52643D39 for ; Wed, 30 Mar 2005 20:03:34 +0000 (GMT) (envelope-from martin@gneto.com) Received: from as6-1-5.kr.m.bonet.se ([83.227.181.30] [83.227.181.30]) by mxfep02.bredband.com with ESMTP <20050330200333.QJSO22685.mxfep02.bredband.com@as6-1-5.kr.m.bonet.se>; Wed, 30 Mar 2005 22:03:33 +0200 Received: from [192.168.10.11] (euklides.gneto.com [192.168.10.11]) by as6-1-5.kr.m.bonet.se (Postfix) with ESMTP id 859A9678E6; Wed, 30 Mar 2005 22:03:32 +0200 (CEST) Message-ID: <424B0614.5000902@gneto.com> Date: Wed, 30 Mar 2005 22:03:32 +0200 From: Martin Nilsson User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; sv-SE; rv:1.7.6) Gecko/20050326 X-Accept-Language: sv, en-us, en MIME-Version: 1.0 To: freebsd-current@FreeBSD.org References: <20050330191824.4c08acc6.aka@veco.ru> <20050330090813.B64732@carver.gumbysoft.com> In-Reply-To: <20050330090813.B64732@carver.gumbysoft.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: ciss(4): speed degradation for Compaq Smart Array [edited] X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 30 Mar 2005 20:03:36 -0000 Doug White wrote / skrev: > > I'd also suggest using a tool like iozone to run your tests instead of dd. > Unless your workload consists of entirely sequential writes this perf test > is worthless. What is wrong with using dd to measure max read/write bandwith of the controller-disk system? I use the following to determine if there are any obvious problems with new hardware: (ad1 should not have any useful data). At the same time I run "systat -v 1" on another console. dd if=/dev/zero of=/dev/ad1 bs=128k dd if=/dev/ad1 of=/dev/null bs=128k On a modern disk this should give numbers in the vicinity of 50MB/s at the beginning of the disk. This tells me in seconds if there is something wrong with the controller, cable, disk (or FreeBSD driver). If I can't get decent bandwith with this simple test, how could I get good performance with any other test program? Regards, Martin