To be able to successfully connect an ESX(i) host to the NFS server, you should make sure that the ESX(i) host has a proper network interface configuration and can access the server on which Veeam vPower NFS Service is running.
When connecting to the NFS server, the ESX(i) host uses a VMkernel interface. That is why ESX(i) host you are using must have a VMkernel interface — otherwise vPower NFS mounting on ESX(i) host will fail.
By default, VMkernel interfaces are not available for non-ESXi versions, so you will have to add them on the ESX host to be able to connect to the NFS server.
•If the NFS server and ESX host are located in the same subnet, the ESX host should have a VMkernel interface in the same IP-network as the NFS server.
•If the NFS server and ESX host are located in different subnets and use a router for network access, in addition to creating a new VMkernel interface, you will have to manually specify routing settings in the IP routing table on the ESX host.
To check whether an ESX host can access the NFS server or not, you can use the vmkping utility on the ESX host. The vmkping utility is similar to the ping tool — the only difference is that ICMP packets are sent via the VMkernel interface, not the service console interface.