1. A disk drive system manager, comprising: means for classifying each of a plurality of storage devices based on the cost; means for checking data on the storage devices to determine whether there is data to be moved from one classification of storage device to another; and means for moving data stored on one or more storage devices of one classification to one or more storage devices of another classification; wherein data is moved to a lower cost storage device based on a decrease in the access pattern of the data.