A method relates to provisioning a cluster system in a virtual machine environment in a storage system. The storage system has a plurality of hosts, a fabric network, a storage array, and a management server. The method includes inputting information on a first cluster system to be defined, the information including selecting a scale unit wherein the first cluster system is to be defined. An inventory database including resource information for the scale unit selected is provided. A virtual I/O (“vIO”) information is provided. The vIO information assigns each of hosts selected for the first cluster system with a vIO device, at least one virtual computer network address, and at least one virtual storage network address. A first cluster definition for the first cluster system in the selected scale unit is created using the vIO information.