Patent ID: 7761425

Claim:
A computer system comprising: a plurality of clients; and a backup server coupled to a single-instance data store, said single-instance store being configured to store backup data for each of the plurality of clients, wherein said backup data includes only a single instance of any data that is stored on the plurality of clients with no duplication in the single-instance store; wherein a client of said clients requesting data backup is configured to: identify a plurality of data segments to be backed up; generate a first list of fingerprints including a fingerprint for each of the plurality of data segments; remove duplicate fingerprints from the first list; and convey the first list to the backup server; wherein in response to receiving the first list, the backup server is configured to: identify first fingerprints included in the first list which match fingerprints of data segments stored in the single-instance data store; and convey a second list to the client, the second list comprising the fingerprints of the first list without the first fingerprints; wherein the client is configured to convey for backup, data segments of the plurality of data segments identified by the second list.