From owner-freebsd-arch Fri Oct 25 13:48:22 2002 Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id C717937B401 for ; Fri, 25 Oct 2002 13:48:20 -0700 (PDT) Received: from mailman.zeta.org.au (mailman.zeta.org.au [203.26.10.16]) by mx1.FreeBSD.org (Postfix) with ESMTP id BCDA743E75 for ; Fri, 25 Oct 2002 13:48:19 -0700 (PDT) (envelope-from bde@zeta.org.au) Received: from bde.zeta.org.au (bde.zeta.org.au [203.2.228.102]) by mailman.zeta.org.au (8.9.3/8.8.7) with ESMTP id GAA08920; Sat, 26 Oct 2002 06:47:58 +1000 Date: Sat, 26 Oct 2002 06:59:09 +1000 (EST) From: Bruce Evans X-X-Sender: bde@gamplex.bde.org To: Julian Elischer Cc: Mark Valentine , Poul-Henning Kamp , "M. Warner Losh" , Subject: Re: cvs commit: src/lib/libdisk Makefile chunk.c write_alpha_disk.c write_i386_disk.c write_pc98_disk.c In-Reply-To: Message-ID: <20021026064258.W5345-100000@gamplex.bde.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Fri, 25 Oct 2002, Julian Elischer wrote: > On Fri, 25 Oct 2002, Mark Valentine wrote: > > > The GEOM naming scheme therefore removes my ability to specify the partition > > in the most natural way for this platform. > I dispute that. > The install code has been using ad0s1a for about 5 years I think. > Very few systems have ad0a in /etc/fstab as we specifically have been > telling people to not do that for ages.. I haven't been using the install code for about 10 years now :-). > Anyway I had a machine where the -current root partition was ad1s4e. > How does the old scheme help me? ad1s3 was also a BSD slice (FBSD3.x) Run fdisk to temporarily change ad1s3 to non-BSD. ad0[a-h] in /etc/fstab for the s4 slice then starts referring to that slice. I have used this to boot backups of partitions (cp /dev/ad0s3 /dev/ad0s4; this invalidates any s3 numbers in the copy of /etc/fstab on the s4 slice, so booting the s4 partition later doesn't work if there are any such numbers, but everything works perfectlyf ad[0-h] is used. At least with my versions of the boot blocks. The switch to using sN in fstab started with changing the boot blocks to pass sN in an incompatible way; I had already fixed the boot blocks in a compatible way and didn't like this or most subsequent changes in this area so I didn't use them. > One scheme I played with was: > /dev/ad0/whole > /dev/ad0/s1 > /dev/ad0/s1/a > /dev/ad0/bsd0 --> s1 > /dev/ad0/s1/whole > /dev/ad0/s2 > /dev/ad0/s2/whole > /dev/ad0/s3 > /dev/ad0/s3/whole > /dev/ad0/s4 > /dev/ad0/s4/whole > > so that /dev/ad0/bsd0/a would always be the root > but I don't know if the new devfs can do that.. > > This had a lot of advantages but blew POLA right out the window :-) Encoding the disk structure in the directory tree would be another mistake. Fotrunately this mistake has already been made, so we know not to repeat it. Bruce To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message