First check if you have nfs  module loaded using the below command,

lsmod | grep nfs

if not present  use

modprobe nfs

Now enable nfs for the vps.
vzctl set 110  --features "nfs:on" --save
Now login to VPS  uing
vzctl enter 110

Run the below commands,
yum -y install nfs-utils nfs-utils-lib
chkconfig --levels 345 portmap on
/etc/init.d/portmap start
NFS is not enable for your vps.