9.1-RC2 - could it be that the installer does not write the MBR?

[Warren Block]

On Sat, 20 Oct 2012, Rainer Duffner wrote:

> Am Fri, 19 Oct 2012 17:11:30 -0400
> schrieb Glen Barber <gjb at FreeBSD.org>:
>
>> On Fri, Oct 19, 2012 at 10:38:41PM +0200, Rainer Duffner wrote:
>>> If I select the "entire disk" for FreeBSD, I think it's a reasonable
>>> assumption that the MBR should replaced, too.
>>> Please don't make people install FreeBSD 9.0 first on disks with
>>> non-FreeBSD MRRs and then upgrade to 9.1.
>>>
>>
>> Can you outline for me in detail what you did when you partitioned
>> your drive during the installation?
>
> I chose "entire disk", then deleted all partitions-suggestions except
> the first one and created my own partitioning scheme.
> (/, swap, var, usr, maybe /var/log and /home, too)
>
>> I have seen your specific issue exactly once, and reliably reproducing
>> the problem has not been successful so far.
>>
>> BTW, what was on the drive before you did the install, if anything?
>
> It had a version of Solaris. Maybe Opensolaris. I don't know exactly.
> And I don't know if it had zfsroot or not. I created a HW-RAID1 with
> the HP P400 controller on it.
> The drives were previously used in another server.
>
> I tried to install 9.1RC2 twice on these disks and it always went back
> to the grub-prompt after reboot.
> Then I installed 9.0 and it's running now.

I don't know if this is the problem, but it is worth pointing out that 
graid(8) is now included in GENERIC.  Leftover hardware RAID metadata 
could make for unexpected results.  For example,
http://forums.freebsd.org/showthread.php?t=35168