1. A method for managing allocation of storage resources in a storage network, wherein the storage network includes physical data storage on one or more storage arrays that are in the storage network, and the network is in communication with one or more hosts and the network further includes a storage network management system that includes a storage virtualizer capable of intercepting and virtualizing an IO stream from the one or more hosts and which storage network management system further includes a storage controller in communication with the storage virtualizer for storage network management, and the method comprises the steps of: the storage network management system allocating one or more virtual data storage volumes for use by a host computer; the storage network management system presenting the virtual data storage volumes to the host computer as representative of available physical storage on the one or more storage arrays, but not allocating physical data storage for the virtual data storage volumes, wherein the virtual data storage volumes can include regions that are either allocated to physical storage or are unallocated to physical storage; the storage management system creating a data storage pool that includes the one and the more data storage arrays, wherein at least one of the plurality of data storage arrays of the data storage pool is connected to another of the plurality of data storage arrays across the network; and upon receiving a write request to the virtual data volume that covers an unallocated region of the volume, the storage network management system allocating physical storage from the storage pool for the virtual data volume, wherein the storage virtualizer enables virtual Storage Area Networks (SAN)s by parsing between front-end SANs and back-end SANs, regardless of physical configuration of the SANs, enabling regions of the virtual data volume to be mapped to block segments of back-end storage elements across virtual SANs; the storage pool comprising physical storage from the plurality of storage arrays enabling storage to be allocated to volumes to be mapped from different physical arrays communicatively coupled by the network; wherein the storage virtualizer has a thin provisioning accelerator which controls loading of a mapping identifying what regions of the virtual volumes are allocated and unallocated and the storage controller has a thin provisioning controller which is responsible for coordination of the physical storage allocation.