TUN module is required to configure VPN tunneling and to configure VPN on a VPS, you need to enable the module from the Hardware node. Login to your Host server and execute the following command:
First check if the TUN module is enabled on the hardware node:
lsmod | grep tun
If not, load the module using modprobe:
modprobe tun
Now, enable the TUN module on a VPS:
vzctl set VEID devices c:10:200:rw save
vzctl exec VEID mkdir -p /dev/net
vzctl exec VEID mknod /dev/net/tun c 10 200
vzctl exec VEID chmod 600 /dev/net/tun
where, VEID is the VPS ID you want to enable the TUN module on.