FreeBSD boot menu is missing

Dag-Erling Smørgrav des at
Thu Nov 27 02:45:12 PST 2008

"Peter Steele" <psteele at> writes:
> Man, I wish I'd known this. I built a whole automated framework around
> this, assuming you couldn't set up the initial mirror drive with a live
> file system. I'll have to try your solution; it is definitely the way to
> go. We are dealing with identical size drives as well so this shouldn't
> be a problem.

Just make sure you leave a few unallocated blocks at the end of the disk
(for gmirror metadata).  In most cases, this happens automatically,
because the size of the disk is not a multiple of the (fake) cylinder
size.  To pick one at random, I have a Maxtor 6B300S0 here with
586112591 LBA sectors where the fake c/h/s geometry only adds up to
586111680 sectors, leaving 911 sectors at the end.

> We don't want to mirror the whole drive, just the OS partitions. I
> decided to go with the full slice mirroring because of what was
> described in this link. If mirroring the partitions in the slice is the
> better way to go, then that's fine my me. 

Mirroring the entire slice is far simpler.  If you mirror individual
partitions, you have to label them *before* you newfs them.

I would mirror the whole drive, though - and I would use ZFS, with which
you can easily transition to larger drives (just replace them one by one
and resilver in between - you can even do it online if your disks are

Dag-Erling Smørgrav - des at

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