Abstract: A virtual storage system, method and computer program product for providing efficient use of storage resources. The system includes a plurality of host systems, an appliance coupled to each of the host systems and at least one physical storage device coupled to the appliance. The appliance manages the allocation of storage space on the physical storage device to the host systems. The appliance allocates virtual storage space to the host systems. The cumulative amount of virtual storage space allocated to the host systems exceeds the actual storage capacity of the physical storage device. The appliance allocates physical space on the physical storage device on an as needed basis.

Abstract: A method, system, and apparatus for accessing a plurality of storage devices in a storage area network (SAN) as network attached storage (NAS) in a data communication network is described. A SAN server includes a first interface and a second interface. The first interface is configured to be coupled to the SAN. The second interface is coupled to a first data communication network. A NAS server includes a third interface and a fourth interface. The third interface is configured to be coupled to a second data communication network. The fourth interface is coupled to the first data communication network. The SAN server allocates a first portion of the plurality of storage devices in the SAN to be accessible through the second interface to at least one first host coupled to the first data communication network. The SAN server allocates a second portion of the plurality of storage devices in the SAN to the NAS server.