Debian 6 GNU/KFreeBSD Grub problems on VirtualBox

Debian 6 was released the other day, with this release they not only released a Linux kernel version but they now support a FreeBSD version as well!
So I decided to install it under VirtualBox and check it out…

The install process went smoothly until I got to the end when it was installing and setting up grub2. It installed ok on the MBR but got an error in the installer while trying to set it up. I jumped into the console to take a look around.

I started off trying to run the update-grub command which fails silently (checking $? shows the return code of 1). On closer inspection I noticed the command created an incomplete grub config named /boot/grub/grub.cfg.new

So all we need to do is finish off this config file. So jump back into the installer and select continue without boot loader, this will pop up a message about what you must set the root partition as when you do set up a boot loader, so take note of it.. mine was /dev/ad0s5.

OK, with that info we can finish off our config file. Firstly lets rename the incomplete one:
cp /boot/grub/grub.cfg.new /boot/grub/grub.cfg


Now my /boot/grub/grub.cfg ended like:
### BEGIN /etc/grub.d/10_kfreebsd ###
menuentry 'Debian GNU/kFreeBSD, with kFreeBSD 8.1-1-amd64' --class debian --class gnu-kfreebsd --class gnu --class os {
insmod part_msdos
insmod ext2

set root='(hd0,1)'
search --no-floppy --fs-uuid --set dac05f8a-2746-4feb-a29d-31baea1ce751
echo 'Loading kernel of FreeBSD 8.1-1-amd64 ...'
kfreebsd /kfreebsd-8.1-1-amd64.gz

So I needed to add the following to finish it off (note this I’ll repeat that last part):
### BEGIN /etc/grub.d/10_kfreebsd ###
menuentry 'Debian GNU/kFreeBSD, with kFreeBSD 8.1-1-amd64' --class debian --class gnu-kfreebsd --class gnu --class os {
insmod part_msdos
insmod ext2
insmod ufs2

set root='(hd0,1)'
search --no-floppy --fs-uuid --set dac05f8a-2746-4feb-a29d-31baea1ce751
echo 'Loading kernel of FreeBSD 8.1-1-amd64 ...'
kfreebsd /kfreebsd-8.1-1-amd64.gz
set kFreeBSD.vfs.root.mountfrom=ufs:/dev/ad0s5
set kFreeBSD.vfs.root.mountfrom.options=rw
}

Note: My root filesytem was UFS, thus the ‘ufs:/dev/ad0s5’ in the mountfrom option.

That’s it, you Debian GNU/kFreeBSD should now boot successfully 🙂