A storage area network system having a data storage means for storing computer data, a storage manager routine running on a client, the storage manager routine having functional elements for directing snapshots to be taken of the computer data on the data storage means, and a snapshot ranking manager for determining characteristics of the snapshots, and for selectively deleting given ones of the snapshots based at least in part on the characteristics of the snapshots. The characteristics of the snapshots might include the type of application that uses the data in the logical volume from which the snapshots were taken, or mission critical aspects of the data.