newbie permissions problems... what's wrong?

[Oliver Iberien]

I am logged in as oliver. I have two extra partitions mounted. Below is the 
section of devfs.conf that has to do with them:

#Allow access to the second disk
own     /dev/ad1s2c     oliver:wheel
perm    /dev/ad1s2c     0666
own     /disk2          oliver:wheel
perm    /disk2          0666

#Allow access to disk3 
own     /dev/ad2s2c     oliver:wheel
perm    /dev/ad2s2c     0666
own     /disk3          oliver:wheel
perm    /disk3          0666

And the permissions that display are:

$ ls -l / | grep disk
drw-rw-rw-   3 oliver  wheel      2048 Jan 16 23:13 disk2
drw-rw-rw-   6 oliver  wheel       512 Dec 21 23:01 disk3

But....

$ mkdir /disk2/storage
mkdir: /disk2/storage: Permission denied

Although as a superuser, it works.

$ sudo mkdir /disk2/storage
Password:
$        

What is going on? 

Thanks,

Oliver