First off, I'd like to clarify that I don't want to store my instances (/var/lib/nova/instances) on an NFS server. I have two private clouds, each with two separate virtual networks on two different subnets and segregated using VXLANs.

Private Cloud#1: 30.0.0.0/16 VXLAN 100
Private Cloud#2: 40.0.0.0/16 VXLAN 101

The underlying physical network connected to the hypervisors lies on the 192.200.0.0/16 subnet. On the same network, I have an Isilon system exporting a number of NFS shares. I'd like to mount these NFS shares on the instances deployed within these private clouds. However, because these clouds have a private virtual network, the 192.200.0.0/16 network is not directly accessible from anywhere within the cloud.

Is there an easy way of doing this? Is there any way of doing this?