8.2-RELEASE-amd64.iso weirdness (help!)

[Michael Powell]

Conrad J. Sabatier wrote:

> I burned a copy of FreeBSD-8.2-RELEASE-amd64-disc1.iso to CD.  It
> booted and ran OK, but I encountered some rather odd behavior in a few
> places:
> 
> As another user mentioned elsewhere, the packages distributions are
> beyond minimal, consisting only of some basic documentation in a
> variety of locales or languages.  No software packages at all.
> 
> Worse still, though, is what I ran across in the
> partitioning/labeling/boot record section of sysinstall; no more
> "dangerously dedicated" mode (unless you go into "expert" mode, which
> is rather a mystery to me), and worse yet, it seems that the options to
> install a plain master boot record or boot manager have no effect
> whatsoever!

"Dangerously dedicated" is being deprecated in favor of more modern ways and 
methods to slice and partition. You should no longer seek to utilize it, and 
I think, if memory serves there was some talk at one time on removing it 
from fdisk and/or sysinstall. 
 
> This is causing me no end of grief, as I'm trying to return this
> machine back to FreeBSD after having run Linux on it for some time.
> The only reason I initially installed Linux was that, at the time I
> bought the machine, neither my hard drive nor my CD drive were being
> recognized by FreeBSD (this has been fixed since then, I'm happy to
> report).
> 
> The really crucial problem I'm facing right now is that I can't get
> Linux's damned "grub" off of my hard drive!   I was hoping that using
> "dangerously dedicated" mode in sysinstall would allow me to overwrite
> the lingering copy of grub on my hard drive that I just can't seem to
> get rid of.  The FreeBSD install works for the most part, despite the
> few oddities mentioned above, but when I try to boot into it afterwards,
> grub seizes control and hangs with an error code.
>
> I've tried numerous workarounds, using boot0cfg and both FreeBSD's and
> Linux's fdisk and friends, but to no avail.  I'm stymied at this point,
> and desperately in need of some advice here.
> 
> Can some sage person out there help me out of this predicament?  Right
> now I feel like I'm doomed to keep running Linux or nothing at all!  I
> am dying to get back to FreeBSD again.
> 

Sounds like you need to zero the first part of your drive. The following is 
best done before installing, rather than afterwards. Either boot a LiveFS CD 
(which I have done before) or, I believe this is also possible from the 
Fixit shell (which I have not tried). In order to gain the ability to 
"force" writes to this area do this at a root prompt:

sysctl kern.geom.debugflags=16

then to zero out the beginning of your disk do:

dd if=/dev/zero of=/dev/adx oseek=1 bs=512 count=1

where x is the drive number. This should get the grub gone. Then install as 
normal. With the grub MBR out of the way you should now be able to install 
FreeBSD bootloader/MBR as you have in the past. 

-Mike