A hierarchically-structured computer mass storage system and method. The mass storage system includes a mass storage memory drive, control logic on the mass storage memory drive that includes a controller and one or more devices for executing a hierarchical storage management technique, a volatile memory cache configured to be accessed by the control logic, and first and second non-volatile storage arrays on the mass storage memory drive and comprising, respectively, first and second non-volatile memory devices. The first and second non-volatile memory devices have properties including access times and write endurance, and at least one of the access time and the write endurance of the first non-volatile memory devices is faster or higher, respectively, than the second non-volatile memory devices. Desired data storage localities on the storage arrays are determined through access patterns and selectively utilizing the properties of the memory devices to match the data storage requirements.