While in the trenches of adding NFS storage to the data-va in Workspace, we uncovered this gem:
This is a great post. It helped us finish the job and assign the primary message store to a NFS volume. We used Microsoft Server 2012 R2 to host the NFS share and needed the server volume to be the primary message store for Workspace. All the steps Andrea takes you through are confirmed in Workspace 1.5.2.