Daniel, Be sure to take into account the amount of data that is encrypted and/or compressed before it is written to the VTL. Same for servers with large numbers of files that don't dedup well, as has already been mentioned. Since the VTL won't be able to dedup or compress it, your dedup ratio on the VTL will be adversely affected. We write those backups to physical tape.
Keith Arbogast Indiana University
