Patent ID: 6421711
Filing Date: 2002-07-16
Classification: G06F,H04L

Abstract:
A data storage subsystem comprising, in combination:data storage; and a storage controller coupled to the data storage for controlling access to the data storage, the storage controller having at least one physical data port for connecting the storage controller into a data network for data transmission between the data storage and host processors in the data network, wherein the storage controller is programmed to provide a plurality of virtual ports that are not physical ports in the data network but that appear to the host processors to be physical ports in the data network that provide access to the data storage and that are connected to the physical data port by a switch in the storage controller for routing storage access requests from the physical data port to the virtual ports; wherein the storage controller is programmed with a permanent network name for each of the virtual ports, is programmed with a temporary network address for each of the virtual ports, and is programmed to route from the physical data port to a specified virtual port a storage access request containing a temporary address that specifies the specified virtual port; wherein the storage controller is programmed to provide access at each virtual port to only a respective assigned subset of the data storage; wherein the storage controller is programmed to permit assignment of more than one virtual port to each host processor such that said each host processor may access storage from every virtual port assigned to said each host processor; and wherein the storage controller is programmed so that none of the virtual ports is assigned to more than one host processor so that not more than one host processor may access the data storage from any one of the virtual ports.