Method and apparatus for undoing changes to computer memory

摘要

Method and apparatus for backing up and restoring data in a computer storage system are disclosed. Changes to segments of memory in a primary copy are tracked. The segments may correspond to how the data is physically stored. Restoration may proceed by returning only those segments that are changed in the primary copy to their state at previous point in time. The backup used for the previous point in time may be a full system backup or a differential backup. A differential backup is one that backs up some segments of memory, but not all of the segments of memory in an element being backed up.