pseudo-device vn

[Mipam]

Hi,

I couldnt find stuff whether the pseudo device vn is by default in the
generic kernel. I didnt find it in GENERIC, but maybe it's otherwise
involved? I guess i need this device to mount a tmpfs like this in /etc

/dev/amrd0s1b /var/amavis   mfs   rw,-s=65536   0   0

where s1b is the swap device.
Should i just put
pseudo-device	vn
in the kernel config file to make this work?
Bye,

Mipam.