Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264490AbTK3Aed (ORCPT ); Sat, 29 Nov 2003 19:34:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264494AbTK3Aed (ORCPT ); Sat, 29 Nov 2003 19:34:33 -0500 Received: from mailhost.tue.nl ([131.155.2.7]:5895 "EHLO mailhost.tue.nl") by vger.kernel.org with ESMTP id S264490AbTK3Aeb (ORCPT ); Sat, 29 Nov 2003 19:34:31 -0500 Date: Sun, 30 Nov 2003 01:34:28 +0100 From: Andries Brouwer To: Andrew Clausen Cc: Szakacsits Szabolcs , Apurva Mehta , Linux Kernel Mailing List , bug-parted@gnu.org Subject: Re: Disk Geometries reported incorrectly on 2.6.0-testX Message-ID: <20031130003428.GA5465@win.tue.nl> References: <20031128045854.GA1353@home.woodlands> <20031128142452.GA4737@win.tue.nl> <20031129022221.GA516@gnu.org> <20031129123451.GA5372@win.tue.nl> <20031129222722.GA505@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20031129222722.GA505@gnu.org> User-Agent: Mutt/1.3.25i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Nov 30, 2003 at 09:27:22AM +1100, Andrew Clausen wrote: > > > Some users, having problems, did mention the usage of 2.6 kernel. If the > > > geometry changed during the fdisk, etc process then it could result also > > > booting problem? > > > > Let me continue to stress: geometry does not exist. > > Consequently, it cannot change. > > Let me continue to stress: geometry DOES exist. Ha, Andrew - you know these things, I know these things - please do not confuse matters. My first letter had as essential content: the Linux 2.6 kernel does not make geometry information available to user space. Thus, if user space asks the kernel and prints an error message in case the answer is unexpected, then such user space is broken under 2.6. There is nothing to gain from asking the kernel. That was a letter for you - parted should be fixed, otherwise there will be a long sequence of users that worry that things might be wrong. My second letter was for Szaka and affirmed that fdisk cannot change this non-existent geometry. You still believe in fairies, I mean, in disk geometry, that is OK, I don't mind, but still, whatever it is you believe in, fdisk cannot change it. > It is an abstract construct that is stored in your BIOS that some > configurations use and need for booting. I am happy with that description. "Disk geometry is: some numbers that your BIOS invents". Of course, details are always more complicated. What the BIOS invents may be dependent on user settings in its setup. There are also numbers that certain operating systems or boot managers invent. Equal to or different from what your BIOS has thought of. > (i.e. have you got any evidence that, say, that 99.x% of Windows XP > installations use LBA to bootstrap?) Just ask yourself this question: does Windows XP require a bootable partition to start below the 1024 cylinder mark? Windows NT4 has such a restriction. Not Windows 2000 or XP. > > Usually booting goes like this: the BIOS reads sector 0 (the MBR) > > from the first disk, and starts the code found there. What happens > > afterwards is up to that code. If that code uses CHS units to find > > a partition, and if the program that wrote the table has different > > ideas about those units than the BIOS, booting may fail. > > Exactly. Good. We agree. Andries - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/