In order to enable an improvement in the access performance of a storage, a storage includes first and second storage devices respectively including first and second storage units to and from each of which data can be written and read, the speed of the first storage device is higher than or equal to that of the second storage device, the first storage device further includes a first storage area for storing management information for access control and management of the second storage unit, the second storage device further includes a second storage area for storing management information for access control and management of the second storage unit, and the storage includes an access control unit which retrieves the management information relating to the second storage unit and used for access to the second storage unit from the first storage area of the first storage device, and retrieves the management information relating to the second storage unit from the second storage area of the second storage device when the management information is not stored in the first storage area, and a capacity control unit which variably sets the allocation between the capacity of the first storage unit and the capacity of the first storage area in the first storage device.