DSS V6 has the ability to perform backups to a Tape Drive to back up the NAS Shares only.

See link below for all about Backup.

http://www.open-e.com/library/how-to-resources/
Open-E Backups
2010.09 Open-E Different Backups

2010.09 Open-E Backup to attached Tape Drive

2010.09 Backup to attached Tape Library using Open-E DSS V6