[patch] NetBSD disklabel support for geom_bsd

[Dag-Erling Smørgrav]

Dmitry Pryanishnikov <dmitry at atlantis.dp.ua> writes:
> Dag-Erling Smørgrav <des at des.no> writes:
> > > 2) (most important) NetBSD disklabel describes partitions not
> > > slice-relative (like ours), but the whole device-relative.
> > I believe we already support that - we did it the same way ourselves
> > prior to GEOM, and geom_bsd should still have compat shims for old
> > labels.
> I've never seen such a support in FreeBSD. There was pre-slice era,
> and you can still create "dangerously dedicated" disk and use
> ad0a-ad0h instead of ad0s1a-h. But NetBSD does something very
> different: it creates disklabel at the start of the _slice_, but
> media offsets in the entries of this label are not slice-relative
> like ours, but absolute media offsets instead, and thus can point
> _outside_ NetBSD slice! Their partitions can thus be aliases for our
> slice devices.

Yes.  The offsets in our disklabels used to be device-relative too.

It is still possible to create dangerously dedicated disks, btw, and
it is still possible to put a disklabel (or even a filesystem)
directly on a device.  GEOM means *more* freedom, not less.

DES
-- 
Dag-Erling Smørgrav - des at des.no