From owner-freebsd-stable Mon Nov 20 9: 9:45 2000 Delivered-To: freebsd-stable@freebsd.org Received: from rover.village.org (rover.village.org [204.144.255.66]) by hub.freebsd.org (Postfix) with ESMTP id 38F6E37B479 for ; Mon, 20 Nov 2000 09:09:43 -0800 (PST) Received: from harmony.village.org (harmony.village.org [10.0.0.6]) by rover.village.org (8.11.0/8.11.0) with ESMTP id eAKH9WQ25302; Mon, 20 Nov 2000 10:09:37 -0700 (MST) (envelope-from imp@harmony.village.org) Received: from harmony.village.org (localhost.village.org [127.0.0.1]) by harmony.village.org (8.9.3/8.8.3) with ESMTP id KAA24067; Mon, 20 Nov 2000 10:09:32 -0700 (MST) Message-Id: <200011201709.KAA24067@harmony.village.org> To: Helge Oldach Subject: Re: Dedicated disks (was: Dangerously Dedicated) Cc: grog@lemis.com, samz@oz.net, stable@FreeBSD.ORG In-reply-to: Your message of "Mon, 20 Nov 2000 17:40:28 +0100." <200011201640.RAA15704@galaxy.de.cp.philips.com> References: <200011201640.RAA15704@galaxy.de.cp.philips.com> Date: Mon, 20 Nov 2000 10:09:32 -0700 From: Warner Losh Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In message <200011201640.RAA15704@galaxy.de.cp.philips.com> Helge Oldach writes: : If I'm not mistaken that's a contradiction. PC BIOS architecture demands : that the first cylinder is not to be used. But obviously DD mode will : use it. So what do you put in a non-bogus partition table? If it says : the first slice starts at cylinder 0 you still have a broken MBR. If : it says it starts at cylinder 1 you are stuck with inconsistency, as : cylinder 0 is in fact in use. : : Seems to me that DD's bogus MBR can't be properly and consistently fixed. The first 8k of the disk is reserved, even in DD. That is to say that the ufs file system starts 8k from the start. boot1 will fit into the first sector. FreeBSD is careful to shoe horn things around the MBR part of the first sector. So you can put something into this MBR. In fact, you have to on some systems or bad things will happen. Right now the bogus MBR that we put on the DD disk might be able to be fixed. I'm not positive that it can be, but it might. I don't have the right kind of machine to do testing of my ideas. Warner To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message