TOWER OF HANOI
The Tower of Hanoi a complex strategy where five tapes are used - called A, B, C, D, and E.
- A - Used Every Other Day
- B - Used Every 4th Day
- C - Used Every 8th Day
- D & E - Used Every 16th Day, Alternating
This ensures that data is available from the last day, 2 days ago, and three other times in history. However, the range of history of backup is dependent on where one is in the cycle.
Consider the following calendar:
This method is clearly confusing, but has the advantage of only requiring 5 tapes. Unless aided by software, this method is not recommended because it is prone to human error.