Methods and apparatus are provided for improving network virtualization in a storage area network. A virtualization engine is divided into a front end virtualization engine and a back end virtualization engine cluster. The front end virtualization is associated with one or more virtual enclosure ports. The back end virtualization engine cluster performs resource intensive virtual address to physical address mapping. Virtualization engine resources can be dynamically added to a back end virtualization engine cluster while presenting a consistent interface to hosts connected to a storage area network.