It is a good idea either to reformat the tape every once in a while or to retension the tape. This keeps your tape in good condition and ensures a good backup and recovery. One last option, which I do not recommend, is setting the backup to compress the data before writing it to the tape. While this option doubles the space on a tape, it can lead to problems with restoring the data later. Choosing Your Options In conjunction with deciding what type of backups to run and when, purchase enough tapes to allow at least a two-week rotation without repeating.
Some consultants recommend a minimum three-week rotation without repeating.
Replace tapes as needed to keep your sets whole. On a dedicated server network, it is relatively easy to schedule and run full-system backups. Because of the ease, these types of backups should be run daily. Under this system, a full-system restore would require you to restore the full backup first and then restore each modified backup, to be certain that all the data possible has been recovered. Backup disks should be stored away from the office, preferably in a fireproof safety deposit box.