From owner-freebsd-stable Tue Nov 21 0:53:46 2000 Delivered-To: freebsd-stable@freebsd.org Received: from mail.rz.uni-ulm.de (sirius-giga.rz.uni-ulm.de [134.60.241.36]) by hub.freebsd.org (Postfix) with ESMTP id CB75537B4C5 for ; Tue, 21 Nov 2000 00:53:41 -0800 (PST) Received: from lilith (lilith.wohnheim.uni-ulm.de [134.60.106.64]) by mail.rz.uni-ulm.de (8.9.3/8.9.3) with SMTP id JAA21381; Tue, 21 Nov 2000 09:53:16 +0100 (MET) Message-ID: <004001c05398$7fdb8080$4011a8c0@wohnheim.uniulm.de> From: "Siegbert Baude" To: , "Roman Shterenzon" Cc: References: <200011210417.VAA07691@freeway.dcfinc.com> Subject: Re: Dangerously Dedicated Date: Tue, 21 Nov 2000 09:53:17 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4133.2400 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Hi Chad, good summary. Only one remark and two additions: > To summarize the summary: The problem comes from the fact that a > PC-BIOS is permitted to insist on an MBR on each drive, and that the > slices in that MBR align on certain boundries whereas FreeBSD > doesn't care about such sillyness but has to use the BIOS to get > launched. I donīt think they do it for their fun and our work to be harder, but as a workaround for other problems the BIOS developers face. So itīs not silly, but a consequence of the PC architecture being defined in a suboptimal fashion. > Simple solution? Don't use DD. > > Slightly less simple? Don't use DD on drives that are in any way > involved with the boot process, but go ahead on data-only drives. As some stated here, the bogus data in a dd-MBR can break booting even on non-boot-disks (i.e. your data-only drives). The mere presence will be tested, detected as faulty and therefore the process stops before anything can be done on user side. For the IA64 no dd will work at all, as a valid MBR is a strict requirement. Ciao Siegbert To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message