Gmirror on a partition of a slice

[n j]

> You can mirror any GEOM providers, which includes disks, slices,
> partitions, encrypted providers, RAID0/RAID3 devices, ZFS volumes, GEOM
> gate devices, and more. Anything you can probe with diskinfo(8) can be
> mirrored (and used for other GEOM classes too). It's more than that. You
> can even mix providers from different GEOM classes, eg:

As Pawel confirmed, partitions can be used as gmirror consumers.
Perhaps the problem I'm running into is that I'm trying to boot off a
gmirror'ed partition? I.e. maybe you can boot if you mirror a whole
disk or a slice, but if you partition a disk and use only one
partition for a mirror, then you can't boot. Could that be the
problem?

Thanks,
-- 
Nino