According to an embodiment, virtual logical units are each provided with correlative data between a virtual logical unit number and a real logical unit number. In response to an access request specifying a virtual logical unit number from a host, a correlated real logical unit number is obtained by referring...http://www.google.de/patents/US7418570?utm_source=gb-gplus-sharePatent US7418570 - Logical unit number increasing device, and logical unit number increasing method
