Virtual ports for data transferring of a data storage system

A machine-readable program storage device that is executable by a storage controller for controlling access to data storage, said 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 program is executable by the storage controller 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 program is executable by the storage controller so that the storage controller will have a permanent network name for each of the virtual ports and a temporary network address for each of the virtual ports, and the program is executable by the storage controller 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 program is executable by the storage controller to provide access at each virtual port to only a respective assigned subset of the data storage;
• wherein the program is executable by the storage controller 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 program is executable by the storage controller 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.

A method of operating a storage controller for controlling access to 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, said method comprising:

• the storage controller receiving storage access requests from the host processors at the physical data port, and inspecting network addresses in the storage access requests to find network addresses of virtual ports in the storage controller to which the storage access requests are directed, and controlling access to the data storage in accordance with the network addresses of the virtual ports to which the storage access requests are directed, wherein the virtual ports are not physical data ports in the data network, but the storage controller is operated to cause the virtual ports to 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 maintains a permanent network name for each of the virtual ports and a temporary network address for each of the virtual ports;
• wherein the storage controller provides access at each virtual port to only a respective assigned subset of the data storage;
• wherein the storage controller permits 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 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.