Patent ID: 7415506

Claim:
A method of operating a storage server that connects a plurality of host computers and a plurality of storage devices, said plurality of storage devices having associated therewith a plurality of physical logical unit numbers (PLUNs), said method comprising: mapping said plurality of PLUNs to a plurality of first media units; creating a second media unit from at least a portion of one or more of said plurality of first media units to facilitate abstract block-storage addressing of storage associated with the plurality of PLUNs; mapping the second media unit to a virtual logical unit number (VLUN) which a host can reference to access data stored in one or more of the storage devices, wherein the plurality of PLUNs are a first storage virtualization level in a storage virtualization hierarchy, the VLUN is a second storage virtualization level in the storage virtualization hierarchy, the plurality of first media units are a third storage virtualization level logically between the first storage virtualization layer and the second storage virtualization layer in the storage virtualization hierarchy, and the second media unit is a fourth storage virtualization level logically between the second storage virtualization layer and the third storage virtualization layer in the storage virtualization hierarchy; and creating storage constructs between the plurality of first media units and the second media unit using the abstract block-storage addressing as a source of blocks that fulfill requirements from the plurality of host computers for predetermined storage attributes and properties at the second storage virtualization level having persistent information stored on the second media unit to describe and store predetermined storage attributes and properties associated with the storage at the second storage virtualization level.