Computer system and its control method

A control method for a computer system, the computer system including a storage system for controlling read access or write access from a host computer to a storage device and a management device for managing a plurality of resources for the storage system and a plurality of users sharing the storage system, the computer system control method comprising the following steps executed by the management device of:

• grouping the plurality of resources respectively to set a plurality of resource groups;
• registering management information of the plurality of resource groups and association information between the plurality of resources and the plurality of resource groups, in the storage system;
• defining a user group for the users and setting an authority to that user group which permits a user belonging to the user group to execute an operation on a resource group allocated to the user group when the user is logged into the storage system;
• in response to receiving a request for allocating a first resource group of the plurality of resource groups to the first user group, using first information to determine whether the first resource group includes both a first resource which is necessary to execution of the authority allocated to the user group and a second resource which is not necessary to execution of the authority allocated to the user group, wherein the first information relates to a necessary resource type for execution of the authority allocated to the user group;
• creating, if it is determined that the first resource group includes both a first resource which is necessary to execution of the authority allocated to the user group and a second resource which is not necessary to execution of the authority allocated to the user group, a second resource group including the first resource without the second resource, and
• representing the second resource group with the first resource group on a display of the management device.