mount -t tmpfs -o nodev,noexec,nosuid -osize=1024M tmpfs /test/
mount --bind /test/ /var/lib/vz/private/100/test/

# vzctl enter 100
entered into CT 100
[root@mta /]# cd /test/
[root@mta test]# touch test
[root@mta test]# ls -lh
total 0
-rw-r--r-- 1 root root 0 May 31 19:00 test
[root@mta test]# exit
logout

[root@vz test]# cd /test/
[root@vz test]# ls -lh
total 0