disklabel+sym=drive.YouCrazy

[Per olof Ljungmark]

On 4.7-stable,
A Compaq ProLiant 1850R + Storage system U2
One hardware raid controller, works fine
Nine 9.1GB disks attached to the internal sym0+1 controller

Trying to prepare disks for vinum with disklabel.

da0 through da3 went fine, added
c: 17767827  0  unused  0 0  # (Cyl.    0 - 1105*)
h: 17767827  0  vinum        # (Cyl.    0 - 1105*)

However, disklabel da4-da8 returns
disklabel: ioctl DIOCWLABEL: Operation not supported by device

Using docs at
http://www.freebsd.org/doc/en_US.ISO8859-1/articles/formatting-media/x66.html
and various vinum documentation as well.
Have iterated the process many times to try to figure out what I'm doing 
wrong but disklabel consistently refuses.

Most grateful for any help.

Per olof