1. A storage apparatus comprising: one or more storage drives for providing real storage resources; and a controller for controlling the one or more storage drives and accesses from a host computer, wherein the controller initializes real storage resources and manages the initialized real storage resources; wherein the controller receives an instruction for allocating an initialized real storage resource to a first virtual storage resource accessed by the host computer; and wherein, in response to the instruction, the controller allocates a first initialized real storage resource which has been initialized in advance prior to the instruction to the first virtual storage resource.