The present invention improves the performance of a storage device by utilizing the special features of different types of volumes. The control part of the storage device constructs a virtual volume in the memory. The virtual volume is constructed by a low-speed volume and a high-speed volume, and has...http://www.google.com/patents/US7380064?utm_source=gb-gplus-sharePatent US7380064 - Storage device and storage device data life cycle control method
