From owner-freebsd-current@FreeBSD.ORG Wed Oct 20 09:51:53 2004 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 6E5AD16A4CE for ; Wed, 20 Oct 2004 09:51:53 +0000 (GMT) Received: from tierra2.ng.fadesa.es (tierra2.ng.fadesa.es [195.55.55.166]) by mx1.FreeBSD.org (Postfix) with ESMTP id 1DBFC43D2D for ; Wed, 20 Oct 2004 09:51:52 +0000 (GMT) (envelope-from fandino@ng.fadesa.es) Received: from [195.55.55.163] ([195.55.55.163]) (authenticated bits=0) by tierra2.ng.fadesa.es (8.12.10/8.12.10) with ESMTP id i9K9pmi3006604 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 20 Oct 2004 11:51:50 +0200 Message-ID: <41763534.2060505@ng.fadesa.es> Date: Wed, 20 Oct 2004 11:51:48 +0200 From: fandino User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7) Gecko/20040616 X-Accept-Language: gl, en, es MIME-Version: 1.0 To: freebsd-current@freebsd.org References: <94275.1098221474@critter.freebsd.dk> In-Reply-To: <94275.1098221474@critter.freebsd.dk> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Authenticated-Sender: user fandino from 195.55.55.163 X-Virus-Scanned: clamd / ClamAV version 0.75.1, clamav-milter version 0.75c on tierra2 X-Virus-Status: Clean Subject: Re: FreeBSD 5.3b7and poor ata performance X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: fandino@ng.fadesa.es List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 20 Oct 2004 09:51:53 -0000 Hello Poul, nice to know you. Poul-Henning Kamp wrote: >>>>Why is a SCSI raid-10 system slower than a plain IDE disk? Something is >>>>wrong here. > > > It has been proven that apples and oranges can indeed be compared, > (for instance spectroscopically, see ISBN 0-7167-3094-4 page 93), :-) > A sequential speed test like the one done here is pointless for > 99.999% of all disks being used in the world. I begun this thread because disk performance in two FreeBSD machines was very low, whilst other operating systems using the same machines were very superior(x2) to FreeBSD. I did several tests with bonnie++ and they confirm this low throughput. A lot of people said "turn off async, softupdates, etc", but nothing brings FBSD performace to a normal level :-( It was just a curiosity test sequential reads using raw devices (just to discard the overhead of filesystem proccesing). It was my down-up test methodology, if sequential read access with raw disks is bad then sequential read acces with filesystems can be seriously affected. > Is your application really writing and reading data only sequentially > to raw disks ? not, they read very large files using the filesystem. > Please do a real and realistic test instead. One which includes > seek times, rotational delay and read/write mixes. I did, please read my posts. If you think I forget something I will be pleased to do some tests for you. http://lists.freebsd.org/pipermail/freebsd-current/2004-October/040568.html http://lists.freebsd.org/pipermail/freebsd-current/2004-October/040740.html > Or at least realize that the quantity you are measuring is very > special case that not many people care about in practice and is in > no way indicative of a general concept like "poor ata performance". perphars a more appropiate subject will be "poor ata performance with sequential read/writes" :-? > There are tools in the ports collection for diskbenchmarking, please > use them rather than come up with some half-assed home-brew stuff. yes, I run dd, bonnie++, bonnie and reports are very clear, there is a problem with performance and the ata system (I think). Regards.