From owner-freebsd-alpha Sun Apr 4 1:23:34 1999 Delivered-To: freebsd-alpha@freebsd.org Received: from herring.nlsystems.com (nlsys.demon.co.uk [158.152.125.33]) by hub.freebsd.org (Postfix) with ESMTP id 2A40714E7E for ; Sun, 4 Apr 1999 01:23:31 -0800 (PST) (envelope-from dfr@nlsystems.com) Received: from localhost (dfr@localhost) by herring.nlsystems.com (8.9.3/8.8.8) with ESMTP id KAA73989; Sun, 4 Apr 1999 10:23:32 +0100 (BST) (envelope-from dfr@nlsystems.com) Date: Sun, 4 Apr 1999 10:23:26 +0100 (BST) From: Doug Rabson To: Simon Shapiro Cc: freebsd-alpha@freebsd.org Subject: Re: disklabel In-Reply-To: <9904031503150Q.22286@nomis.simon-shapiro.org> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-alpha@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Sat, 3 Apr 1999, Simon Shapiro wrote: > On Sat, 03 Apr 1999, Doug Rabson wrote: > >On Fri, 2 Apr 1999, Simon Shapiro wrote: > > > >> Is it my imagination or lack of attention, or a problem? > >> > >> It appears that if I disklabel a drive on a PC, the label will not be > >> visible on an Alpha? > >> > >> Why do that? Linux fdisk (on the alpha) is a bit broken, so I thought > >> to disklabel on a PC and move the disks. No cigar. > >> > >> So, either this is the case, or the two are so incompatible that they > >> write/read totally different areas on the disk. > >> > >> BTW, Linux thinks that there is partition 4 on the disks. fdisk on the > >> FreeBSD-i386 side confirms that. > >> > >> Yes, I followed the handbook guide and wiped out the first megabyte of > >> /dev/da16, then disklable -Br, etc. No cigar. > > > >The disklabel lives in different places on the two architectures. For > >i386, it is at block 1, offset 0 and for alpha it is at block 0, offset > >64. This is mainly for compatibility with OSF1 and NetBSD but it makes > >some kind of sense since the first block isn't cluttered up with > >executable code on the alpha. > > > >To add to the fun, disklabel -Br does completely different things on the > >alpha (like installing alpha executables instead of i386 ones...). > > Figured as much :-) > > Question still remains how to make a diskpack compatible between the > two? > > There are several uses to this, clustering being not the least of them. The only way I can think of is to put two labels on the disk, one in block zero offset 64 and one in block one, offset zero. The disk would have to be 'dedicated', i.e. no fdisk partition table. -- Doug Rabson Mail: dfr@nlsystems.com Nonlinear Systems Ltd. Phone: +44 181 442 9037 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message