From owner-freebsd-questions@FreeBSD.ORG Mon May 3 11:41:21 2004 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 4952016A4CE for ; Mon, 3 May 2004 11:41:21 -0700 (PDT) Received: from smtp.rdsnet.ro (smtp.rdsnet.ro [62.231.74.130]) by mx1.FreeBSD.org (Postfix) with ESMTP id 253E743D45 for ; Mon, 3 May 2004 11:41:19 -0700 (PDT) (envelope-from itetcu@apropo.ro) Received: (qmail 10123 invoked by uid 89); 3 May 2004 18:36:07 -0000 Received: from unknown (HELO rdsnet.ro) (62.231.74.131) by 0 with SMTP; 3 May 2004 18:36:07 -0000 Received: (qmail 13723 invoked from network); 3 May 2004 18:41:18 -0000 Received: from unknown (HELO buh.cameradicommercio.ro) (81.196.25.19) by mail.rdsnet.ro with SMTP; 3 May 2004 18:41:18 -0000 Received: from it.buh.cameradicommercio.ro (it.buh.cameradicommercio.ro [192.168.0.10]) by buh.cameradicommercio.ro (Postfix) with ESMTP id 8A8576130; Mon, 3 May 2004 21:40:43 +0300 (EEST) Received: from localhost (localhost.buh.cameradicommercio.ro [127.0.0.1]) by it.buh.cameradicommercio.ro (Postfix) with ESMTP id F13AB2BC; Mon, 3 May 2004 21:44:58 +0300 (EEST) Received: from it.buh.cameradicommercio.ro ([127.0.0.1])port 10024) with ESMTP id 66301-05; Mon, 3 May 2004 21:44:58 +0300 (EEST) Received: from it.buh.cameradicommercio.ro (localhost.buh.cameradicommercio.ro [127.0.0.1]) by it.buh.cameradicommercio.ro (Postfix) with SMTP id 5EB3124C; Mon, 3 May 2004 21:44:58 +0300 (EEST) Date: Mon, 3 May 2004 21:44:58 +0300 From: Ion-Mihai Tetcu To: "Kevin A. Pieckiel" Message-Id: <20040503214458.7af4a022@it.buh.cameradicommercio.ro> In-Reply-To: <20040430180659.GA6873@SDF.LONESTAR.ORG> References: <20040430180659.GA6873@SDF.LONESTAR.ORG> X-Mailer: Sylpheed version 0.9.10claws (GTK+ 1.2.10; i386-portbld-freebsd5.2) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Virus-Scanned: by amavisd-new at it.buh.cameradicommercio.ro cc: freebsd-questions@freebsd.org Subject: Re: What is bps/cpg? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 03 May 2004 18:41:21 -0000 On Fri, 30 Apr 2004 14:07:00 -0400 "Kevin A. Pieckiel" wrote: > I was reading the man page for bsdlabel, specifically looking for what the > bps/cpg value for a new filesystem should be. The man page states: > > bps/cpg > For 4.2BSD file systems, the number of cylinders in a cylinder > group. For LFS file systems, the segment shift value. Defaults > to 16 for partitions smaller than 1GB, 64 for partitions 1GB or > larger. > > Okay. Sure. That leaves a few questions: > > 1. What is the purpose of cylinder groups? > 2. What are "reasonable" values for this parameter? > 3. Why, if the default is 16 or 64, did sysinstall create my various > filesystems (on various machines) with values of 8, 28552, or 32776? > > I'm just trying to understand why this value is set to these numbers by > sysinstall, and to what I should set this value when I add a HDD to a > computer. Try reading the comments in /usr/src/sys/ufs/* beginning with /usr/src/sys/ufs/ffs/fs.h. Do it with a piece of paper and a pencil at hand ;-) -- IOnut Unregistered ;) FreeBSD "user"