Need Vinum help

[Thomas Smith]

I think I have the process of creating a Vinum volume but I'm missing 
something.

My config file (config1) contains:

drive a device /dev/ad0
volume root
  plex org concat
    sd length 36g drive a

When I run /vinum create config1/ I get the error "Can't initialize 
device a: Operation not supported by device"

I've huffed, and I've puffed, and I've blown over many a page of docs 
and can't seem to figure out what gives.

The FStype in /etc/fstab for / is ufs--as I understand it, Vinum needs 
an FStype of vinum. I haven't been able to find any docs describing how 
to make this occur.