The invention is directed to a primary data storage system for use in a computer network in which a network allows user computers to transfer data to and/or from the primary data storage system. In one embodiment of the invention, the storage processor operates to analyze the data associated with write block commands that relate to different storage locations in a data store system that is associated with the primary data storage system so as to identify the potential writing of the block(s) of the same data to the data store system and prevent the writing of such blocks of data.