Date: Fri, 25 Oct 2002 14:07:36 +0100 (BST) From: Mark Valentine <mark@thuvia.demon.co.uk> To: Poul-Henning Kamp <phk@critter.freebsd.dk>, Dag-Erling Smorgrav <des@ofug.org> Cc: jhb@freebsd.org (John Baldwin), cvs-all@freebsd.org, cvs-committers@freebsd.org, Takahashi Yoshihiro <nyan@jp.FreeBSD.org>, Bakul Shah <bakul@bitblocks.com>, Bruce Evans <bde@zeta.org.au> Subject: Re: cvs commit: src/lib/libdisk Makefile chunk.c write_alpha_dis Message-ID: <200210251307.g9PD7al6069458@dotar.thuvia.org> In-Reply-To: <17285.1035549439@critter.freebsd.dk>
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> From: Poul-Henning Kamp <phk@critter.freebsd.dk> > Date: Fri 25 Oct, 2002 > Subject: Re: cvs commit: src/lib/libdisk Makefile chunk.c write_alpha_dis [Perhaps this should move to -arch?] > In message <xzp8z0mk88q.fsf@flood.ping.uio.no>, Dag-Erling Smorgrav writes: > >Mark Valentine <mark@thuvia.demon.co.uk> writes: > >> The MBR partitioning is a feature of the MBR boot code, not of the BIOS. > > > >Wrong. Plenty of recent-issue BIOSen (particularly on laptops) go > >down in flames if the MBR does not contain a valid partition table. That doesn't change the way the DOS boot code works. > Some even if the MBR doesn't contain the correct magic partitions for > sleep/save images and the like. I can see that the BIOS might implement an additional restriction for suspend-to-disk. Does it play ball better if this feature is disabled (where possible)? > Long way or short way, MBR is not optional on the first disk on the > PC architecture and consequently we should not try to hide the fact > that it is there. A DOS partitioned boot sector is by no means mandatory on all PC systems. I guess we differ here in that I'm saying we *should* hide this implementation detail by default for consistency with other platforms, and that the only requirement for encoding two levels of partitioning schemes in a logical device name is for those who wish to use the (mis-?)feature which currently allows multiple BSD disklabels on a disk (and how many people is _that_?), or for the convenience of referring to another DOS partition without an explicit disklabel entry for it. > For all other disks, people can usually label them as they like, > (now including: "not at all") and GEOM will name the resulting > devices in an intuitive and consistent way. There is simply no need to enforce this inconsistency on disks which do not require it, including PC boot disks. It may prove safer to use an MBR for the default install configuration, but this doesn't prevent using the "compatbility slice" device names. People who do obscure things can edit fstab, rather than obfuscate the common case. As I've pointed out elsewhere, this hardwiring of partition numbers in /etc/fstab has required me to reach for the fixit floppy more than once, a problem which doesn't occur with the compatibility device names. Cheers, Mark. -- Mark Valentine, Thuvia Labs <mark@thuvia.co.uk> <http://www.thuvia.co.uk>; "Tigers will do ANYTHING for a tuna fish sandwich." Mark Valentine uses "We're kind of stupid that way." *munch* *munch* and endorses FreeBSD -- <http://www.calvinandhobbes.com>; <http://www.freebsd.org>; To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
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