In a system comprising a first storage system providing plural first logical volumes including real logical volume and a virtual logical volume with a host, a second storage system having a second logical volume, and a management computer, when the first storage system receives an access request to the virtual logical volume, it accesses a second logical volume associated with the virtual logical volume. In this system, when the management computer receives a request to guard one of the plural first logical volumes, it checks whether a target first logical volume of the request is a real logical volume or a virtual logical volume, in case of the virtual logical volume, generates and provides a possible at least one option to guard the virtual logical volume by considering a program for volume guard, which each of the first storage system and the second storage system has.