1. A method for non-disruptively migrating data in a storage area network from a physical source storage array to a virtual array spanning one or more physical destination storage arrays, the one or more destination storage arrays being physically separate from the source storage array, the source storage array having physical source ports, each physical source port having a physical port address used by hosts to access data residing at the source storage array, the method comprising: generating the virtual array spanning the one or more destination storage arrays for receiving a copy of all data resident at the source storage array, the virtual array being configured with at least as many virtual ports as physical source ports of the source storage array and with at least as many logical units of storage (LUNs) as LUNs of the source storage array, each LUN of the source storage array corresponding to one of the LUNs of the virtual array and being equal in storage capacity to that corresponding LUN, each virtual port having a virtual port address used by hosts to access data residing at the one or more destination storage arrays; copying all data resident in the LUNs of the source storage array to corresponding LUNs in the virtual array; inducing a name server database, used by hosts to learn name and address associations of devices, to be rebuilt to associate port names of the physical source ports of the source storage array with the virtual port addresses of the virtual ports such that the virtual array spanning the one or more destination storage arrays appears to a host as the source storage array.