Acronis Backup for Linux Server - User Guide - Manual (Page 49)

49 Copyright © Acronis International GmbH, 2002-2014
By default, a backup is not deleted as long as it has dependent backups that must be kept. For
example, if a full backup has become subject to deletion, but there are incremental or differential
backups that depend on it, the deletion is postponed until all the dependent backups can be deleted
as well.
For more information, see Retention rules (p. 72).
4.2.6.4 Tower of Hanoi scheme
At a glance

Up to 16 levels of full, differential, and incremental backups

Next-level backups are twice as rare as previous-level backups

One backup of each level is stored at a time

Higher density of more recent backups
Parameters
You can set up the following parameters of a Tower of Hanoi scheme.
Schedule Set up a daily (p. 60), weekly (p. 62), or monthly (p. 64) schedule. Setting up schedule
parameters allows for the creation of simple schedules (example of a simple daily
schedule: a backup task will be run every 1 day at 10 AM) as well as more complex
schedules (example of a complex daily schedule: a task will be run every 3 days, starting
from January 15. During the specified days the task will be repeated every 2 hours from
10 AM to 10 PM). Thus, complex schedules specify the sessions on which the scheme
should run. In the discussion below, "days" can be replaced with "scheduled sessions".
Number of levels Select from 2 to 16 backup levels. See the example stated below for details.
Roll-back period The guaranteed number of sessions that one can go back in the archive at any time.
Calculated automatically, depending on the schedule parameters and the numbers of
levels you select. See the example below for details.
Backup type Specifies what backup types the backup levels will have

Always full - all levels of backups will be full.

Full/Differential/Incremental - backups of different levels will have different types:
- Last-level backups are full
- Backups of intermediate levels are differential
- First-level backups are incremental
Example
Schedule parameters are set as follows

Recur: Every 1 day

Frequency: Once at 6 PM
Number of levels: 4
Backup type: Full/Differential/Incremental
This is how the first 14 days (or 14 sessions) of this scheme's schedule look. Shaded numbers denote
backup levels.
1 2 3 4 5 6 7 8 9 10 11 12 13 14