can't mount root during freebsd-update 7.0 -> 8.1 on amd64

[Joost Bekkers]

On Tue, Dec 07, 2010 at 01:26:56PM -0600, Steve Randall wrote:
> > > 2010/12/5  <joost at jodocus.org>:
> > >> Hi
> > >>
> > >> I'm trying to upgrade a amd64 box from 7.0-RELEASE to 8.1-RELEASE with
> > >> freebsd-update. After the first reboot the 8.1R GENERIC kernel loads
> > >> (I'm
> > >> using a custom kernel, so at this point the generic kernel is loaded
> > >> manually)
> > >> It then claims it can't mount /
>
> Your disk was at one time "dangerously dedicated" and later converted
> to MBR. But there is still an obsolete BSD label in block 1 of the disk.
> 
> # dd if=/dev/zero of=/dev/ad4 seek=1 count=1

Yes, that fixed it. 

Thanks

-- 
greetz Joost
joost at jodocus.org