From owner-freebsd-fs@FreeBSD.ORG Fri Aug 27 06:02:39 2010 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 5F5681065675; Fri, 27 Aug 2010 06:02:39 +0000 (UTC) (envelope-from bruce@cran.org.uk) Received: from muon.cran.org.uk (unknown [IPv6:2001:470:1f08:679::2]) by mx1.freebsd.org (Postfix) with ESMTP id 0A42E8FC23; Fri, 27 Aug 2010 06:02:38 +0000 (UTC) Received: from unknown (client-82-31-24-1.midd.adsl.virginmedia.com [82.31.24.1]) (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by muon.cran.org.uk (Postfix) with ESMTPSA id BD6035F15; Fri, 27 Aug 2010 06:02:34 +0000 (UTC) Date: Fri, 27 Aug 2010 07:02:33 +0100 From: Bruce Cran To: Doug Barton Message-ID: <20100827070233.000075a8@unknown> In-Reply-To: <4C7715D0.10604@FreeBSD.org> References: <4C7715D0.10604@FreeBSD.org> X-Mailer: Claws Mail 3.7.4cvs1 (GTK+ 2.16.0; i586-pc-mingw32msvc) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: freebsd-fs@freebsd.org Subject: Re: Difference of opinion about my disk geometry X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 27 Aug 2010 06:02:39 -0000 On Thu, 26 Aug 2010 18:33:04 -0700 Doug Barton wrote: > Below are what the various OS' think about the disk. (Ignore the fact > that the 3rd partition has an unknown type, that used to be a FreeBSD > partition that seems to have been mangled by grub2, which I'm going > to fix later.) When I run FreeBSD fdisk from sysinstall I get the > following message: > It is safe to use 484521/16/63 as the disk geometry blah blah blah, > Do you want to change this? > I've been saying no, but now I think what I want to do is say yes, > and change it to 30401/255/63 which is what Windows and Linux think > it is, and repartition the whole drive. Does that sound reasonable? > > Of course this prompts me to ask the questions of why are we looking > at this differently than Windows and Linux, and what are the > advantages/disadvantages to the 2 methods? CHS is totally obsolete, and can be ignored for anything but really old computers I think - LBA has been used since about 2000. If you use the modern partitioning tool in Windows, diskpart.exe, you don't get told about the geometry at all; if you use gpart in FreeBSD you get told about the fwheads and fwsectors but partitions are specified in terms of an offset. -- Bruce Cran