ACRONIS BACKUP AND RECOVERY 10 SERVER FOR WINDOWS - UPDATE 3 User Manual page 30

For example, if there are five rings labeled A, B, C, D, and E in the puzzle, the solution gives the
following order of moves:
The Tower of Hanoi backup scheme is based on the same patterns. It operates with Sessions instead
of Moves and with Backup levels instead of Rings. Commonly an N-level scheme pattern contains (N-
th power of two) sessions.
So, the five-level Tower of Hanoi backup scheme cycles the pattern that consists of 16 sessions
(moves from 1 to 16 in the above figure).
The table shows the pattern for the five-level backup scheme. The pattern consists of 16 sessions.
The Tower of Hanoi backup scheme implies keeping only one backup per level. All the outdated
backups have to be deleted. So the scheme allows for efficient data storage: more backups
accumulate toward the present time. Having four backups, you can recover data as of today,
yesterday, half a week ago, or a week ago. For the five-level scheme you can also recover data
backed up two weeks ago. So every additional backup level doubles the maximal roll-back period for
your data.
Tower of Hanoi by Acronis
The Tower of Hanoi backup scheme is generally too complex to mentally calculate the next media to
be used. But Acronis Backup & Recovery 10 provides you with automation of the scheme usage. You
can set up the backup scheme while creating a backup plan.
Acronis implementation for the scheme has the following features:

up to 16 backup levels

incremental backups on first level (A) - to gain time and storage savings for the most frequent
backup operations; but data recovery from such backups takes longer because it generally
requires access to three backups

full backups on the last level (E for five-level pattern) - the rarest backups in the scheme, take
more time and occupy more space in storage

differential backups on all intermediate levels (B, C and D for five-level pattern)
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