freebsd bootloader / boot0cfg and multiple disks?

Chris Brennan xaero at
Mon Dec 20 18:25:45 UTC 2010

On Mon, Dec 20, 2010 at 1:07 AM, Henrik Hudson <lists at> wrote:

> I'm trying to get the FreeBSD boot loader to to boot off multiple
> disks, but I can't seem to get it to see my 3rd disk.
> FreeBSD 8.2-PRE amd64; stock kernel with sound card, ahci and PF added
> disk layout:
> ada0: freebsd main install (/, /tmp, /var, /usr, /home, swap)
> ada1: freebsd data disk
> ada2: win7 with ada2s1 being the "boot" 100MB, ada2s2 and ada2s3
> being partitions
> How can I get boot0cfg to try and boot the 3rd disk, ada2s1? I added the
> 3rd
> disk after already having the first 2 setup and installed. Normally,
> I install Windows first and boot0cfg picks it up fine, but not this
> time :)
> The man page shows how to install a boot MBR on a disk and to
> reference the slices, but I can't seem to see how to reference a 2nd
> or 3rd disk. The default install picks up the 2nd disk (FreeBSD
> data), but obviously can't boot from that. So, it does seem to be
> able to redirect to other disks.
> I tried doing a boot0cfg -Bv -s 1 ada2, but that seems to just
> install a MBR on ada2 and it never gets picked up on ada0 boot menu.
> grub isn't supported on amd64 and grub2 seems to be all "wizards"
> and secondary "config" files :(

Did you mark ada0(s1) as bootable? Sounds like you might have missed that
and marked the wrong disk/slice as bootable.

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