Storage+Compute: Existing VxRail clusters can be expanded by adding additional VxRail nodes, which adds additional compute and storage resources to the shared pool.

Compute-only: VMware does not allow non-VxRail hosts to become part of a VxRail cluster. This means that installing and enabling the vSAN VMkernel on hosts in a VxRail cluster that is not contributing storage, so vSAN datastores can be presented to these hypervisor hosts as well, is not an option at this time.

Storage-only: N/A; A VxRail node always takes active part in the hypervisor (compute) cluster as well as the storage cluster.