NFS is used as the storage protocol in vSphere environments.
SMB3 is used as the storage protocol in Hyper-V environments.

In virtualized environments In-Guest iSCSI support is still a hard requirements if one of the following scenarios is pursued:
- Microsoft Failover Clustering (MSFC) in a VMware vSphere environment
- A supported MS Exchange 2013 Environment in a VMware vSphere environment

Microsoft explicitely does not support NFS in both scenarios.