Patent ID: 7174425

Claim:
In a computer system including a first storage apparatus having at least one first volume and a second storage apparatus having at least one second volume, a computer coupled to at least one of the first and second storage apparatus, wherein the first storage apparatus, the second storage apparatus, and the computer are coupled together via Fibre Channel interfaces, a management computer for managing capacity of the volumes in the computer system through a management network, comprising: a network interface arranged to be coupled to the management network; a processor coupled to the network interface; a memory coupled to the processor; and a display coupled to the processor; wherein the processor collects, via the network interface, capacity information representing the capacity of each first and second volume from the first and second storage apparatus, respectively; the processor collects, via the network interface, relationship information which defines relationships between the first volumes and the second volumes, the relationship information including at least two of the following: first relationship information indicating a first volume that is a virtual volume related to a second volume that is a data volume arranged to store data for the computer and to be accessed by the computer addressing the virtual first volume related thereto; second relationship information indicating a first volume and a second volume that are synchronized to store data for the computer with each other; and third relationship information indicating a first virtual volume that is a data volume to store data for the computer and is unrelated to any second volume; the processor sums the capacity of the first and second volumes to obtain a total capacity of the volumes of the first and second storage apparatus; the processor subtracts from the total capacity, the capacity of any second volume indicated by the first or second relationship information; and the processor outputs the result of the subtraction to the display as the effective total capacity of the volumes of the first and second storage apparatus.