1. A computer system comprising: a first storage system, which includes hard disk drives configuring a first logical unit managed by a first management computer; a first management computer coupled to the first storage system storing first management authority information; a second storage system, which includes hard disk drives configuring a second logical unit managed by a second management computer; a second management computer coupled to the second storage system storing second management authority information; and a third management computer coupled to the first management computer and the second management computer, storing resource correspondence information, which third management computer manages the first logical unit and the second logical unit as storage resources via the first management computer and the second management computer, wherein the first management computer is configured to manage the first logical unit as a first management resource based on the first management authority information indicating management authorities of a plurality of administrators to the first management resource, wherein the second management computer is configured to manages the second logical unit as a second management resource, based on the second management authority information indicating management authorities of the plurality of administrators to the second management resource, wherein the third management computer is configured to manage the storage resources based on the resource correspondence information, which indicates correspondences between the storage resources including the first logical unit and the second logical unit and management computers include the first management computer and the second management computer, wherein, the third management computer is configured to receive a management authority update request identifying at least one certain storage resource which is one or more of the storage resources and a certain administrator which is one or more of the plurality of administrators, wherein, the third management computer is configured to select one of the first management computer and the second management computer, which manages the at least one certain logical unit associated with the at least one certain storage resource, and to send an update request of a management authority of the certain administrator about the at least one certain logical unit to the one of the first management computer and the second management computer, based on the resource correspondence information, and wherein the one of the first management computer and the second management computer, which receives the update request, is configured to update the one of the first management authority information and the second management authority information about the at least one certain logical unit.