Patent ID: 8069326

Claim:
A virtual volume relocation system comprising: a storage comprising a plurality of pools and having one or more virtual volumes formed on the pools, the pools being formed of one or more general volumes, wherein, in response to a writing instruction to the one or more virtual volumes, the storage allocates a storage area from the one or more general volumes forming the pools; and a management server that manages the virtual volumes, wherein the management server comprises: a storage section that stores a tier definition that consists of a plurality of conditions for classifying the pools into tiers, wherein the conditions include at least a definition of a usage amount increase bias that is predicted in accordance with a trend in usage increase of a tier relative to the other tiers in the pool; a prediction section that predicts time periods in consideration of the conditions in the storage section, the time periods indicating an amount of time before the pools are exhausted in a configuration after relocation of the virtual volumes is executed, wherein the prediction section estimates an increase in a usage amount of the pools based on the usage amount increase bias defined per tier; a selection section that selects pools as destination candidates based on a result of prediction by the prediction section; and a relocation section that executes the relocation of the virtual volume to one of the destination candidate pools selected by the selection section.