Mounting partition as /var/spool/mail

[Patrick Kirk <patrick@kirks.net>]

 Hi all,
 
 A colleague at work has offered to prove he can crash
 my debian server if I give him a user account.  Its a kind
 of RH vs Debian thing so I've said he can try.  One 
 way he might try is simply to fill the hdd so I have 
 given him a 10 MB partition as home.  In case he tries 
 to do the same with fetchmail, I want to set up a 
 partition with 100MB as /var/spool/mail.
 
 Steps so far:
 
 cp -a /var/spool/mail /spare100
 umount /spare100
 mount -t ext2 /dev/etc /var/etc
 chown root /var/spool/mail
 
 But it doesn't work as the partition is read-only for users.
      
 Is what I am trying to do possible and if so how have I
 messed up permissions, assuming that is what I've messed up?
        
 Thanks in advance,
	 
 Patrick