Patent attributes
A replication process using snapshots to maintain information regarding changes made to a production data set following a point in time. In some embodiments, the production data set may be a file system and the snapshot may store information relating to changes made to both previously-allocated and newly-allocated data blocks. When a change is made to a previously-allocated data block, the original contents for the data block may be copied to a save volume prior to being overwritten by the new data, while for a newly-allocated data block no data may be copied to the save volume. An entry may also be created in a map identifying each changed data block. A replication process may then read the block map to identify data blocks storing new data to should be replicated to a replication data set, such that the replication data set remains a copy of the production data set.
