update to 8.0-RELEASE --> partition gone

[Ben Morrow]

Quoth Marcel Moolenaar <xcllnt at mac.com>:
> On Dec 15, 2009, at 2:20 PM, Steven Friedrich wrote:
> >> 
> > FreeBSD 8.0 no longer supports "dangerously dedicated" disks.
> 
> This is not true. The problem is that sysinstall creates an invalid
> "dangerously dedicated" disk, as demonstrated by doing:
> 	# fdisk ad8
> 	(shows FreeBSD slice information)
> 
> 	# bsdlabel ad8
> 	(shows valid but empty disk label)
> 
> Marian just needs to wipe out the second sector on the disk to
> remove the BSD disklabel that prevents the kernel from using
> the master boot record in the 1st sector. This exposes ad8s1.
> This then will pick up the BSD disklabel in sector 65 (i.e.
> the second sector in slice 1) to give ad8s1a...

Are you able to clarify exactly what is no longer working in 8? I've
read things here and there about dangerously dedicated disks no longer
being supported, but no detail about what exactly had changed. You seem
to be implying here that there is only a problem if there are invalid
and/or overlapping labels on the disk; elsewhere I have read that disks
without an MBR aren't supported at all (I presume the faked-up MBR on a
GPT disk counts). If I currently have a working ad2{b,c,d,e}, will they
be picked up by 8, or would I have to repartition slightly smaller with
a useless MBR slice in front?

Ben