Patent ID: 8918585

Claim:
A management system for a storage apparatus coupled to a host device, wherein the storage apparatus comprises: a virtual volume, which is a virtual logical volume configured of multiple virtual areas; a pool configured of multiple actual area groups of different performances related to I/O processing; and a controller which, in response to an access command from the host device, accesses an actual area allocated to a virtual area identified by the access command, wherein, if the access command from the host device is a write command, the controller allocates an actual area from the pool to a virtual area identified by the write command, wherein the controller manages pool status information, which is information showing which actual area is allocated to which virtual area and a load of the access commands related to each of the virtual areas, wherein the management system comprises: a storage resource; and a processor coupled to the storage resource, wherein the storage resource stores capacity management information, which is information showing the current storage capacity of each actual area group, and wherein the processor: (A) estimates the used capacity of each actual area group at a point of time in the future based on the pool status information at multiple points of time from past to present and an access load threshold defining a range of access load for each actual area group; (B) calculates, for each actual area group, an installed/removed amount which is a difference between the estimated used capacity and the current storage capacity shown by the capacity management information; and (C) performs processing based on the result of the calculation in the (B), wherein one or more access load thresholds are determined based on a pool performance which is a response time of the pool and an installation cost which is a financial cost at least one of for obtaining installing capacity and for consumed electricity.