Tape is dead. Seriously. Backing up direct to tape requires long backup windows, good network performance, constant purchase of new tapes, and expensive Backup Exec licenses, and even if you can get the latter to work, restoring from tape at best takes an hour--if the tapes you need are on site. Making tape backup work requires staging to disk with snapshots--and once you make that investment, you might as well use it as your primary backup and take advantage of replication, cloning, and other features that the disk filer probably has. Tape is useful only for last-ditch offsite data storage or vaulting, and even then it's still a security risk.