According to the present invention, techniques for performing security functions in computer storage subsystems in order to prevent illegal access by the host computers according to logical unit (LU) identity are provided. In representative embodiments management tables can be used to disclose the Logical Unit in the storage subsystem to the host computers in accordance with the users operational needs. In a specific embodiment, accessibility to a storage subsystem resource can be decided when an Inquiry Command is received, providing systems and apparatus wherein there is no further need to repeatedly determine accessibility for subsequent accesses to the Logical Unit. Many such embodiments can maintain relatively high performance, while providing robust security for each LU.