1. A computer program product for managing data storage having a plurality of storage pools containing extents of data objects, the computer program product comprising a computer readable storage device having computer readable program code embodied therein that executes to perform operations, the operations comprising: storing a first deduplicated data object in a primary storage pool; determining the duration of time that the first data object has resided in the primary storage pool; comparing the determined duration of time to a predetermined time interval; after the determined duration of time meets or exceeds the predetermined time interval, determining if the first data object has an extent referenced by another data object; and determining whether to move the first data object from the primary storage pool to a secondary storage pool as a function of whether the first data object has an extent referenced by another data object after the determined duration of time meets or exceeds the predetermined time interval.