Tape Requirements for Daily Incremental, Weekly Cumulative Schedule

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

If you need to restore the complete file system, you need the following tapes: the level 0, the most recent Friday tape, and all the daily tapes since the last Friday tape, if any.