Subject: Re: Dynamic SCSI ids (was: A possible way of handling...)
To: Jonathan Stone <>
From: Bill Studenmund <>
List: tech-kern
Date: 05/12/1997 14:37:23
> (Bill Studenmund) writes:
> >> Another possability of this scheme is to permit having 4 (maybe 3?)
> >> partitions per device. If your system uses lots of ccd's, you can then
> >> have twice as many hd's hooked up at once. If ccd's can be partitioned,
> >> you get the best of both worlds.
> >How about on the i386 we add the concept of slices?  It sure would be
> >nice to have a FreeBSD partition, BSDI, and NetBSD all on the same
> >disk, and be able to share home and source directories.
> My NZ$0.05:
> I think that would be a great idea. I have a couple of i386 machines
> with NetBSD and Linux partitions. Slices would be a much nicer way to
> manage such systems.  As it is, mapping the non-BSD BIOS partitions is
> burning burning too many of the per-drive partitions allowed by the
> BSD disklabel.

I agree that this change'd be good, though I think it's seperate from
dealing with more partitions.

> >Using a slice is, on the i386, a BIOS partition, which is then divided
> >into the standard ones.
> >
> >/dev/wd0a would reference the first (and probably only) NetBSD partition
> >by default in that case.
> >From what I know of FreeBSD and Solaris/x86 use of slices, that
> doesn't sound like the right mapping.  Slices should be partitionable
> with a BSD-style disklabel at the start of each *BSD partition.  We
> should also be able to access `foreign' slices, or partitions of
> `foreign' slices.
> Sounds to me like we're going to want 32 (BSD) partitions per i386
> HDA, allowing up to 8 partitions per slice.  Or possibly more.
> This would also let us kill the `d=whole drive, c=bsd parition' misfeature.
> Maybe NetBSD could just copy whatever FreeBSD does here.  That would
> be a big overall consistency win for those (like Darren Reed) who use both.

For dealing with multiple slices, I vote for our following whatever
FreeBSD's done.

Might it be time to extend minor numbers to greater than 256 per major?

Take care,