vinum unable to find root

[dave]

Hello,
    Trying to set up FreeBSD on a mirrored raid1 root. I have followed the
section in ch12 of "The Complete FreeBSD" added the lines to loader.conf,
altered the disklabel, and ran fsck on /dev/vinum/root which worked fine.
When i changed /etc/fstab from /dev/ad0s1a to /dev/vinum/root and rebooted i
am getting the error:

setrootbyname failed
ffs_mountroot can not find root
root mount failed: 6

and then i am asked for manual root specifications. When i enter ufs:ad0s1a
or ufs:vinum/root i get a kernel panic and the system reboots. My disklabels
and fstab are below, any suggestions welcome.
Thanks.
Dave.

original disklabel
# /dev/ad0s1:
8 partitions:
#        size   offset    fstype   [fsize bsize bps/cpg]
  a:   245760  1048576    4.2BSD     2048 16384 15368
  b:  1048576        0      swap
  c: 78156162        0    unused        0     0         # "raw" part, don't
edit
  d:   524288  1294336    4.2BSD     2048 16384 32776
  e:  6291456  1818624    4.2BSD     2048 16384 28552
  f: 70046082  8110080    4.2BSD     2048 16384 28552

modified disklabel
# /dev/ad0s1:
8 partitions:
#        size   offset    fstype   [fsize bsize bps/cpg]
  a:   245760  1048576    4.2BSD     2048 16384 15368
  b:  1048295        281      swap
  c: 78156162        0    unused        0     0         # "raw" part, don't
edit
  d:   524288  1294336    4.2BSD     2048 16384 32776
  e:  6291456  1818624    4.2BSD     2048 16384 28552
  f: 70046082  8110080    4.2BSD     2048 16384 28552
  g: 78156146        16    vinum        0     0         # "raw" part, don't
edit

original fstab
# Device  Mountpoint FStype Options  Dump Pass#
/dev/ad0s1b  none  swap sw  0 0
/dev/ad1s1b  none  swap sw  0 0
/dev/ad0s1a  /  ufs rw  1 1
/dev/ad0s1f  /home  ufs rw  2 2
/dev/ad1s1g  /home2  ufs rw  2 2
/dev/ad1s1d  /root2  ufs rw  2 2
/dev/ad0s1e  /usr  ufs rw  2 2
/dev/ad1s1f  /usr2  ufs rw  2 2
/dev/ad0s1d  /var  ufs rw  2 2
/dev/ad1s1e  /var2  ufs rw  2 2
/dev/acd0  /cdrom  cd9660 ro,noauto 0 0

modified fstab
# Device  Mountpoint FStype Options  Dump Pass#
/dev/vinum/swap  none  swap sw  0 0
/dev/ad1s1b  none  swap sw  0 0
/dev/vinum/root  /  ufs rw  1 1
/dev/vinum/home  /home  ufs rw  2 2
/dev/ad1s1g  /home2  ufs rw  2 2
/dev/ad1s1d  /root2  ufs rw  2 2
/dev/vinum/usr  /usr  ufs rw  2 2
/dev/ad1s1f  /usr2  ufs rw  2 2
/dev/vinum/var  /var  ufs rw  2 2
/dev/ad1s1e  /var2  ufs rw  2 2
/dev/acd0  /cdrom  cd9660 ro,noauto 0 0

vinum configuration file
drive asteroid device /dev/ad0s1g
volume root
plex org concat
sd len 245760s driveoffset 1048560s drive asteroid
volume swap
plex org concat
sd len 1048295s driveoffset 265s drive asteroid
volume home
plex org concat
sd len 70046082s driveoffset 8110064s drive asteroid
volume var
plex org concat
sd len 524288s driveoffset 1294320s drive asteroid
volume usr
plex org concat
sd len 6291456s driveoffset 1818608s drive asteroid