Patent ID: 8244996

Claim:
A storage apparatus, comprising: a first storage device that primarily stores data; a second storage device, having a property differing from the first storage device, that secondarily stores the data; and a control device that controls a data migration between the first storage device and the second storage device, wherein the control device includes: a storage section that stores attribute information for each item of content of the data stored in the first storage device, the attribute information including an attribute that indicates whether the respective item of content shares data with one or more other items of content; a priority determination section that sets a priority for the data migration from the first storage device to the second storage device based on the attribute information; and a data migration section that causes data to migrate from the first storage device to the second storage device based on the priority, wherein the priority determination section sets a migration priority for data such that an item of content that shares data with one or more other items of content has a lower priority than an item of content that does not share data with one or more other items of content.