From SolusVM

Changing Namesevers on all OpenVZ Virtual Servers

This will set the resolver ip's in all the vps to the Google resolvers.

#!/bin/sh

VPS="$(cd /vz/private/ && echo *)"
 for VPS in $VPS; do
  vzctl set $VPS --nameserver 8.8.8.8 --nameserver 8.8.4.4 --save
 done;