Patent ID: 8452932

Claim:
A method of backing-up an active data volume in a multi-tiered data storage system, said method comprising: storing data in said active data volume of said multi-tiered data storage system by storing data in a first data tier comprising a first set of data chunks, said first set of data chunks stored in a first tier memory system, storing data in a second data tier comprising a set of second tier data slices stored in a second tier memory system, said second tier data slices may be combined to create data chunks in a second set of data chunks, storing data in a third data tier comprising a set of third tier data slices, said third tier data slices stored in bulk storage, said third tier data slices may be combined with said second tier data slices to create data chunks in a third set of data chunks; creating a snapshot volume of said active data volume; creating a fingerprint data map of said snapshot volume, said fingerprint data map comprising an ordered list of data slice fingerprints, each of said data slice fingerprints comprising a statistically unique fingerprint of an associated data slice in said snapshot volume; copying unique data slices of said associated data slices to a back-up storage system; and storing said fingerprint data map in said back-up storage system.