Volume allocation scheme

A management device selects a storage device having a plenty of unallocated storage regions, selects a target using a port having a small allocation quantity from the storage device targets, and allocates the target, an initiator, and a storage region. When the number of targets and the allocated storage regions prepared by the storage device is within a predetermined number, the storage device manages the storage device as an allocation candidate. When the predetermined number is exceeded, the exceeding one is excluded from the allocation candidate. When the number of storage devices excluded from the allocation candidate has reached a certain number, the management device manages a new storage device and a new storage region as an allocation candidate.