Before sending data to a media server, the Simpana 8 backup agent also performs the blocking and hash calculations and sends the hash values along with the data. The media server then identifies duplicate blocks and stores the data on any disk resource available to Simpana -- DAS, SAN, or NAS.
This approach should use somewhat less host CPU cycles than Avamar or PureDisk, which conduct a more complex conversation with the data store server(s) to identify unique blocks before sending them but will send more data over the net. Simpana will globally de-dupe to minimize network traffic between media servers so remote offices with local backup pools will use less network bandwidth than those without.
When a job spools datasets off to tape, it copies the blocks that contain data from any of the files or other objects in the dataset and creates a new hash catalogue that it writes to the tape. The tape can then be read by any Simpana 8 media server, but restores will require some cache disk space.
Simpana is content aware, seeing all the file system metadata as backups or archive jobs run and taking that into account when dividing the data up into blocks to de-dupe.