System Administration Guide: Devices and File Systems

Tape Requirements for Daily Incremental, Weekly Cumulative Schedule

With this schedule, you need at least 9 tapes if you want to reuse daily tapes, which is not recommended. Preferably, you need 21 tapes if you save weekly tapes for a month: one tape for the level 0, 4 tapes for the Fridays, and 4 or 16 daily tapes.

If you need to restore the complete file system, you need the following tapes: