1. A method of data progression in a disk drive system, comprising the steps of: determining a cost of operating for each of a plurality of data storage devices; classifying each of the plurality of data storage devices based on the cost; defining a default size for data storage blocks; checking data storage blocks of the defined default size on the data storage devices to determine whether a given storage block comprises data to be moved from a data storage device of a first classification to a data storage device of a second classification; and moving the data stored at the given storage block on the data storage device of the first classification to the data storage device of the second classification.