Re: turning off COMPAT_386BSD_MBRPART in disklabel

[Thor Lancelot Simon <tls%panix.com@localhost>]

On Thu, Feb 03, 2011 at 08:01:34AM +0000, David Laight wrote:
> 
> The disklabel describes the partition layout of the disk (not the type
> 169 mbr partition), it has to be saved on the disk.
>
> Saving it is ALL the partitions (and, IIRC, anywhere else it manages to find
> a copy!) avoids confusion and allows the pbr boot code to find it.

But this is potentially very dangerous, in combination with
COMPAT_386BSD_MBRPART, because FreeBSD considers labels to be per-"slice"
(per fdisk-partition) and uses the 0x165 partition type.  So if we are not
very careful, we can hopelessly wreck FreeBSD installations in other
MBR partitions.