5.3-BETA1, jails and devfs

[Rob MacGregor]

Probably a stupid question, however...

I've got my first jail running under 5.3-BETA1 and am trying to lock down /dev,
as per the advice in the jail man page.  All attempts fail however:

# devfs ruleset 10
devfs ruleset: ioctl DEVFSIO_SUSE: Operation not permitted
# devfs rule apply hide
devfs rule: ioctl DEVFSIO_RAPPLY: Operation not permitted

I'm pretty sure I've missed something obvious in a man page, but having re-read
them a few dozen times I'm darned if I can work it out.  Any help appreciated.

TIA

-- 
 Rob MacGregor (BOFH) [PGP key ID 0x1E51BF5A]
        If I cannot bend Heaven, I shall move Hell.
                           -- Publius Vergilius Maro (Virgil).