A storage device has a storage medium, a plurality of read-write
mechanisms, a quality monitoring and book-keeping unit and a scheduling
unit. The plurality of read-write mechanisms is coupled to the storage
medium. The quality monitoring and book-keeping unit is coupled to the
plurality of read-write mechanisms and is adapted to monitor at least one
performance parameter associated with each read-write mechanism during
operation. The scheduling unit is coupled to the quality monitoring and
book-keeping unit. The scheduling unit is adapted to rank each of the
plurality of read-write mechanisms according to the at least one
performance parameter and to responsively schedule use of a read-write
mechanism according to its rank.