Gmirror on a partition of a slice

[n j]

Hello,

this question is somewhat related to my earlier question regarding
gstripe during install where the common conclusion was to gmirror the
root partition and gstripe the rest as you can't boot from a gstripe'd
volume (which I later confirmed in
http://misc.allbsd.de//Flyer/FreeBSD/PDF/en/flyer-en-fbsd-geom.pdf).

Using http://www.onlamp.com/pub/a/bsd/2005/11/10/FreeBSD_Basics.html
and http://people.freebsd.org/~rse/mirror/ as pointers, as well as
handbook and man pages, I tried to set up gmirror on a partition of a
slice the following way (using identical 1Gb disks da0 & da1), but
couldn't get the OS to boot from gmirror'ed partition. I'm probably
doing something wrong here, but I've googled my a** off and haven't
found any hints for gmirror'ing a partition, though the documentation
states that either disks, slices or partitions should work just fine
as gmirror consumers. The man and handbook pages cover examples using
entire disks and when I use entire disk for gmirror, the setup works
fine; when trying to gmirror a partition, it just won't boot. If
anyone succeeded in gmirror'ing a partition, please tell me how.

In short:

1) install FreeBSD on 1st disk /dev/da0s1a

2) create slice on 2nd disk fdisk -BI /dev/da1

3) bsdlabel -w -B /dev/da1s1

4) edit BSD label to create a partition for gmirror
a:  1000000       16    4.2BSD       2048     16384    8
c:  2097120        0    unused        0     0         # "raw" part

5) gmirror label -h -n -b round-robin gm0 /dev/da1s1a to create mirror

6) fdisk -BI /dev/mirror/gm0 to create a slice in gm0

7) bsdlabel -w -B /dev/mirror/gm0s1 to create root partition
a:  995951   16     4.2BSD     2048 16384 8
c:  995967    0       unused        0     0         # "raw" part

8) newfs, mount, dump/restore to /dev/mirror/gm0s1a, modify fstab,
loader.conf, create boot.config to boot off mirror

9) reboot

... and at that point I get "Not ufs" and "No /boot/loader".

Thanks for any input!

-- 
Nino