/vz 192.168.0.0/255.255.255.0(rw,no_root_squash,sync,no_subtree_check)
/usr 192.168.0.0/255.255.255.0(rw,no_root_squash,sync,no_subtree_check)

fw-office:~# mount -t nfs 192.168.0.3:/usr/ /mnt/; umount /mnt/  
fw-office:~# mount -t nfs 192.168.0.3:/vz/ /mnt/; umount /mnt/   
mount: 192.168.0.3:/vz/ failed, reason given by server: Permission denied
umount: /mnt/: not mounted

==> /var/log/daemon <==
Nov 24 08:43:18 cluster-office2 mountd[8515]: authenticated mount request from 192.168.0.1:990 for /usr (/usr)
Nov 24 08:43:19 cluster-office2 mountd[8515]: authenticated unmount request from 192.168.0.1:992 for /usr (/usr)
Nov 24 08:43:27 cluster-office2 mountd[8515]: authenticated mount request from 192.168.0.1:995 for /vz (/vz)