iSCSI is the native StarWind HCA storage protocol, as StarWind HCA provides block-based storage.
NFS can be used as the storage protocol in VMware vSphere environments by leveraging the File Server role that the Windows OS provides.
SMB3 can be used as the storage protocol in Microsoft Hyper-V environments by leveraging the File Server role that the Windows OS provides.

In both VMware vSphere and Microsoft Hyper-V environments, iSCSI is used as a protocol to provide block-level storage access. It allows consolidating storage from multiple servers providing it as highly available storage to target servers. In the case of vSphere, VMware iSCSI Initiator allows connecting StarWind iSCSI devices to ESXi hosts and further create datastores on them. In the case of Hyper-V, Microsoft iSCSI Initiator is utilized to connect StarWind iSCSI devices to the servers and further provide HA storage to the cluster (i.e. CSV).


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.