update to 8.0-RELEASE --> partition gone

[Xin LI]

On Tue, Dec 15, 2009 at 4:08 PM, Ben Morrow <ben at morrow.me.uk> wrote:
> 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?

My $0.02: what about labelling them, say, tunefs -L on UFS partitions,
and glabel for swap, then change corresponding entry in fstab.  Say:

 - Start into single user
 - tunefs -L root /
 - reboot into single user <--- reboot required after tuning /
 - mount -u /; mount -a
 - vi /etc/fstab and change "/dev/ad0a" to "/dev/ufs/root"
 - umount -a
 - tunefs -L other partitions
 - mount -a
 - vi /etc/fstab and change the rest
 - reboot

Cheers,
-- 
Xin LI <delphij at delphij.net> http://www.delphij.net