From owner-freebsd-scsi@FreeBSD.ORG Thu Jun 7 09:14:58 2007 Return-Path: X-Original-To: freebsd-scsi@freebsd.org Delivered-To: freebsd-scsi@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 2F4AE16A46E for ; Thu, 7 Jun 2007 09:14:58 +0000 (UTC) (envelope-from berni@ask-us.at) Received: from luxus.ask-us.at (luxus.ask-us.at [213.235.218.3]) by mx1.freebsd.org (Postfix) with ESMTP id BA48D13C4CC for ; Thu, 7 Jun 2007 09:14:57 +0000 (UTC) (envelope-from berni@ask-us.at) Received: from [192.168.0.129] ([213.129.242.166]) by luxus.ask-us.at with Microsoft SMTPSVC(6.0.3790.1830); Thu, 7 Jun 2007 11:14:56 +0200 Message-ID: <4667CCA6.3030508@ask-us.at> Date: Thu, 07 Jun 2007 11:15:18 +0200 From: Bernard Buri User-Agent: Thunderbird 2.0.0.0 (X11/20070526) MIME-Version: 1.0 CC: freebsd-scsi@freebsd.org References: <20070606143430.GA31380@schottelius.org> <466717E5.2070909@ask-us.at> <20070607083147.GA25624@schottelius.org> In-Reply-To: <20070607083147.GA25624@schottelius.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 07 Jun 2007 09:14:56.0072 (UTC) FILETIME=[508C2480:01C7A8E4] Subject: Re: Recommened U320 SCSI controller (pci-x)? X-BeenThere: freebsd-scsi@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SCSI subsystem List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 07 Jun 2007 09:14:58 -0000 Nico -telmich- Schottelius wrote: > Bernard Buri [Wed, Jun 06, 2007 at 10:24:05PM +0200]: >> Hi! >> >> Not only for FreeBSD, I have the best experience with the mpt fusion >> based cards, concerning performance and compatibility/reliability. > > Do you have some card names? Searching for the 53c010 on the lsi logic > page was quite confusing, because it seems to link to other cards that > use the amr driver, which is another chip, afaiu. > >> Currently, we have a subversion server running FreeBSD 6.2 without any >> problems on an mpt based raid controller. I believe it is U160 though. > > Ok. We are trying to run a high-load mailserver over here and thus the > disk i/o is a big issue (and locking up the server a big problem). > > Nico > We have a "Feiertag==no one is in office" today, and there was a technical problem yesterday evening. Some servers are down obviously so I cannot lookup which product is built in exactly. I can find out tomorrow though. Are you looking for hardware raid, or do you want to do software raid ? Another question that comes to my mind: Did you analyze the disk i/o any further ? My experience with FreeBSD shows, that upgrading the main memory generously (2 or 4 GB) will allow the system to fill the buffer cache with file data, while leaving the "Namei lookup cache" constrained to some degree. If you run systat -vmstat 1, you can see everything on one place: 1.) On the bottom, you can see the actual disk utilization. 2.) Above, you can watch the "Namei" cache behaviour. 3.) On top, you see Free Memory, that is: memory that is not used at all So, on my Mac mini which has a very slow disk I face the following situation: I run du -h -d1 /usr/ports to fill the Namei cache. Now I watch the statistics in systat and run du again: 1.) I see actual disk i/o happening on my drive 2.) I see Namei cache hits dropping to ~45% 3.) I see about 300MB of memory unused. Most of the mailserver softwares are using many small files, and I guess that the lookup cache should improve the overall performance more than a fast drive. If you see low Namei hit rates, perhaps there is information available on how to tune the cache ?