Unable to mount the root fs on stable/8 r264339, GENERIC kernel, with MBR, FreeBSD slice, and UFS volume labels

[Warren Block]

On Sat, 12 Apr 2014, Trond Endrestøl wrote:
> On Fri, 11 Apr 2014 23:09-0600, Warren Block wrote:
>>
>> My first guess would be missing bootcode in the BSDlabel slice.  But I may
>> have missed that when I missed earlier parts of this thread.
>
> How? Why? The system has booted FreeBSD stable/8 for the last five
> years using MBR, slice, and UFS labels. Why should it stop all of a
> sudden?

Accidental overwrite or (long shot) disk sector failure?  I don't know, 
really.  Check the smartctl output for that disk.  The BSDlabel bootcode 
can be reinstalled without harming the filesystems.  I'd still make a 
backup first, something questionable is going on.

Inclusion of the geom_raid kernel module for the first time, and old 
RAID metadata on the disk?  That would show in /var/log/messages or 
dmesg.  If that's the problem, it can be disabled in loader.conf or at a 
boot prompt with kern.geom.raid.enable=0.