From owner-freebsd-performance@FreeBSD.ORG Fri Sep 10 13:21:49 2004 Return-Path: Delivered-To: freebsd-performance@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id F133916A4CE for ; Fri, 10 Sep 2004 13:21:49 +0000 (GMT) Received: from freebee.digiware.nl (dsl390.iae.nl [212.61.63.138]) by mx1.FreeBSD.org (Postfix) with ESMTP id 30E4943D41 for ; Fri, 10 Sep 2004 13:21:49 +0000 (GMT) (envelope-from wjw@withagen.nl) Received: from [212.61.27.71] (dual [212.61.27.71]) by freebee.digiware.nl (8.12.10/8.12.10) with ESMTP id i8ADLkEg072092; Fri, 10 Sep 2004 15:21:47 +0200 (CEST) (envelope-from wjw@withagen.nl) Message-ID: <4141AA6A.2070802@withagen.nl> Date: Fri, 10 Sep 2004 15:21:46 +0200 From: Willem Jan Withagen User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.7.2) Gecko/20040804 Netscape/7.2 (ax) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Geert Hendrickx References: <20040831133551.GA86660@lori.mine.nu> <4134B312.8030309@pacific.net.sg> <1093958674.680.2.camel@book> <20040831183908.GA87694@lori.mine.nu> In-Reply-To: <20040831183908.GA87694@lori.mine.nu> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit cc: freebsd-performance@freebsd.org cc: oceanare@pacific.net.sg Subject: Re: spreading partitions over multiple drives X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 10 Sep 2004 13:21:50 -0000 Geert Hendrickx wrote: >>Not for this usage. >> >> >>>Fragmentation may be LESS of a problem with UFS, but a moving target >>>like one big /usr (incl src, obj, ports) will get fragmented as well. >>> >>> >>This is how you see it. I have not heard that there is any tool to help >>here. >> >>I would not call this fragmentation. It is more like spreading the files >>from one directory all over the disk. >> >> > >Ok but the effect is the same: constant movement of the head. > > I would expect a bigger system to cache just about all file access during 'make buildworld'. Even when building things with -j 64 I can not get my dual-opteron 1Gb system get without free pages. And as such most files will only be read once, and object output will be "slowly" synced on the disks. Disk I/O rearly becomes the bottleneck, most of the time I'm missing raw CPU cycles. And I have everything on 1 large 200Gb disk. >>>Splitting up partitions would reduce this fragmentation (as you are >>>essentially defining some "super large blocks"), and may increase >>>filesystem stability in case of crashes etc. >>> >>> >>> >>It might not affect stability but it increases the chances to fix a >>problem in case of a crash. >> >> > >Yes I meant stability of the filesystem not of the running OS. > > >Ok but the original question was about spreading partitions amongst >multiple disks, not pro/con splitting partitions on one disk. :-) > > My major problem with a lot of partitions has always been that one way or antoher I outgrow a partition and then all of a sudden the logic needs to be skewed for space reasons. Finaly disks start to grow to the size where this becomes a moot point. 10Gb for /usr will last me until we get to the next step of disk-sizes. Having things on different spindles will of course be a major plus. --WjW