From owner-freebsd-stable@FreeBSD.ORG Sun Nov 25 14:49:01 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 AED6716A57E for ; Sun, 25 Nov 2007 14:49:01 +0000 (UTC) (envelope-from askbill@conducive.net) Received: from conducive.net (conducive.net [203.194.153.81]) by mx1.freebsd.org (Postfix) with ESMTP id 763A313C468 for ; Sun, 25 Nov 2007 14:49:01 +0000 (UTC) (envelope-from askbill@conducive.net) Received: from cm218-253-81-177.hkcable.com.hk ([218.253.81.177]:60627 helo=pb.local) by conducive.net with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.63 (FreeBSD)) (envelope-from ) id 1IwIcJ-000F7I-Vf for freebsd-stable@freebsd.org; Sun, 25 Nov 2007 14:37:52 +0000 Message-ID: <474988C0.4070909@conducive.net> Date: Sun, 25 Nov 2007 14:37:52 +0000 From: =?UTF-8?B?6Z+T5a625qiZIEJpbGwgSGFja2Vy?= User-Agent: Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.8.1.2) Gecko/20070221 SeaMonkey/1.1.1 MIME-Version: 1.0 To: freebsd-stable@freebsd.org References: <47496BE1.8080206@modula.no> In-Reply-To: <47496BE1.8080206@modula.no> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: SAS5IR performance issue with Dell 860 X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 25 Nov 2007 14:49:01 -0000 Espen Tagestad wrote: > Hi, > > We recently bought 3 new Dell 860 servers with the onboard SAS5/IR SATA > RAID-controller. They seem to be quite well spec'ed servers with > management and everything - but I am experiencing av major performance > issue with the disc i/o. On write I get at max 7-8MB/sec, while read > gives a bit more (11MB/sec). I tried first with 6.2-RELEASE, and then > upgraded to 6.3-PRERELEASE without any better results. > > I am aware of some discussion around this issue on these two maillists > in the spring earlier on this year, but I have not been able to find any > good resolution. My old firewall/router at home equipped with a 733Mhz > Pentium 3 processor and a old 40GB IDE harddrive made around year 2001 > performe better. Is there anybody out there with the same problem who > has solved this issue? Could it be that this is solved in 7.0? > > Thanks in advance. > You haven't indicated what drives are on that controller, or how (RAID?) arranged.,, what sort of on-drive or on-controller cahce and policy. Nor how you measured the '..performs better', which a single can often do compared to several of the possible RAID configurations. Otherwise, those are not actually 'bad' numbers for sustained I/O - especially if anything-at-all is going on at the same time that needs to intervene and move the r/w heads 'elsewhere' - however briefly. More info? Bill