It is made possible to update information registered in a database of iSNS, SLP and the like in response to a configurational change in a storage device, and for a host computer to discover a disk volume. In response to changes in contents of operation to alter a storage configuration such as in creating or deleting a volume or LUN, contents of the alteration are reflected in the database of iSNS or SLP. Also, in response to a change in setting of LUN masking, a discovery domain of iSNS or attribute values of SLP are updated so that the host computer can discover the disk volume. Also, objects and services are reregistered periodically according to a registration period of iSNS or lifetime of SLP to prevent registered contents from expiring.