Patent ID: 6868398

Claim:
A method for renting and charging a storage system, in which an owner of a storage system rents and charges the storage system to a user of the storage system, wherein said storage system is set in a user site and a charging system is set in an owner site, and wherein said storage system has a channel control unit which is connected to a host computer and responds to requests from the host computer; a cache memory which stores data sent by the host computer under control of said channel control unit; a disk control unit which controls a plurality of storage devices so as to store said data stored in said cache memory into said storage devices and a shared memory which stores control information according to said channel control unit and said disk control unit, comprising the steps of: holding requests of using a plurality of volumes made from said storage devices in said shared memory, which are set by an operating unit connected to said channel control unit or disk control unit; recording information of a state of use of said volumes into a use management table in accordance with said requests of using said volumes; reading said information of said state of use by referring to said use management table under control of said channel control unit or said disk control unit; sending said read information of said state of use under control of said channel control unit or said disk control from the storage system to the charging system of said owner; sending a user identification ID, a usable volume of said volumes for said user at an initial setting stage, and an additional volume that cannot be used unless said user conducts a new operation for adding the additional volume with said operating unit from said storage system in said user site to the charging system of said owner in said owner site; and charging said user of said user identification ID for said usable volume for said user at the initial setting stage and said additional volume added by said new operation by said charging system in said owner site.