FreeBSD boot menu is missing

Peter Steele psteele at
Wed Nov 26 14:46:50 PST 2008

>The phrase "and copy the file systems over to the mirror" worries
>me. Do you actually copy the file systems, or do you let the mirror
>system do it for you? In particular, are you mirroring file systems or
>the entire disk? Because the boot blocks aren't part of any file
>system, so you won't have copied them over, hence you'll be getting
>whatever boot software the second drive has installed.

I'm more or less using the approach described here:

This assumes you have an existing OS installed on one drive of a
multi-drive system. You then use gmirror to create mirror devices on a
second drive to match the partitions of the boot drive, transfer the
data to the newly established mirror, adjust /etc/fstab on the mirrored
root partition to mount the appropriate mirrored devices, then reboot,
telling the boot loader to boot from the mirrored drive instead of the
original boot drive (via an entry in boot.config). After it comes up,
you can then add the original boot drive to the mirror (and any other
drive if there are more than two drives that you want to mirror) using
gmirror insert. This all works fine, except I'm not getting the boot
menu. I know this isn't part of the mirroring, but it is a step I need
to perform as part of the whole process. The question is what do I need
to do to make sure the appropriate boot loader is setup?

>My recommendation for gmirror is to set up one drive to boot from,
>then us gmirror label to create a gmirror device on each partition
>(excluding swap). Edit /etc/fstab to use the gmirror devices thus
>created, and reboot to make sure it's working properly. It will
>initially boot from the disk device (pretty much required until
>gmirror is started), then switch to the mirrored root partition.  Now
>use gmirror insert to add the matching partitions on the second disk,
>and let gmirror update the bits on the second drive. You'll need to
>copy the boot blocks from the first drive to the second drive by hand
>if you want to boot off the second drive.

I think you are describing more or less the same process here.

>FWIW, these days I use ZFS on 64 bit systems in preference to UFS and

We plan to switch our application over to ZFS, but not this close to a

>Final comment: if you didn't ask on -questions first, this would have
>been more appropriate there than here.

My bad. I'm new in this arena and didn't know where the appropriate
place to post. I'm use -questions in the future.

More information about the freebsd-hackers mailing list