At minimum a VxRail deployment consists of 3 nodes. From there the solution can be scaled one or more nodes at a time. The first 4 cluster nodes must be identical.

Scaling beyond 32 nodes no longer requires a Request for Product Qualification (RPQ). However, an RPQ is required for Stretched Cluster implementations

If using 1GbE only, a storage cluster cannot expand beyond 8 nodes.

For the maximum node configuration hypervisor cluster scale-out limits still apply: 64 hosts for VMware vSphere.

VxRail 4.7 introduces support for adding multiple nodes in parallel, speeding up cluster expansions.