tar a complete drive excluding one directory

[Oliver Fuchs]

Hi,

I want in FreeBSD RELEASE 5.2.1 tar a complete / system except one directory
e.g. /mnt where I want to store the tar archive.
In linux I do:

cd /
tar cvzf /mnt/root.bak-$(date +%Y%m%d).tar.gz . --exclude=proc --exclude=mnt

Trying this in FreeBSD is not accepted because tar is still trying to tar
the /mnt directory and the to be made archive.

What I am doing wrong?

Oliver
-- 
... don't touch the bang bang fruit