FreeBSD 9.1 won't boot with a graid error

[Warren Block]

On Thu, 1 Aug 2013, F. Senault wrote:

> Hi everybody.
>
> I've just upgraded a box from FreeBSD 9 to 9.1 via freebsd-update.
>
> At the first reboot, the machine stopped with messages about GRAID :
>
> GEOM_RAID: Promise: Subdisk kjihgfedcba`_^]\[ZYXWVUTSRQPONM:0-ada0 state
> changed from NONE to ACTIVE
>
> The trick is that I've never setup any kind of RAID on that old box...
>
> Is there a way to completely disable GEOM_RAID loading on boot ?

Boot into the loader (option 2 at boot menu).  Enter:

   set kern.geom.raid.enable=0
   boot

That should allow it to boot, and can be added to /boot/loader.conf. 
I'm not sure of an easy way to clear the metadata for a permanent fix.

Apparently some manufacturers use motherboard RAID to test drives, so 
the metadata may have been on the drive from the factory.