Thanks for the question. I would try to upgrade to RCU 2.1 (it was released yesterday) as it may fix the issue you are experiencing. Unfortunately support for RCU with vSphere will be not be available until the next release of RCU. Anecdotally I have heard that 2.1 may work for NFS with vSphere... I can't guarantee anything as we don't officially support it but for your test environment it may give you what you need.