Using the GUI
The GUI doesn't have much options, the most you can do is go to the Scheduling tab and set the Keep setting to either "At least a year" or "At least 6 months". The application will manage storage space, by deleting old backups when it finds that the storage is low on space.
If you are comfortable with the command line, you can run the following command in the terminal:
duplicity remove-older-than <time> [options] [--force] target_url
You can find more details about the options, and what you can do from the command line by running
To quote the manual:
Delete all backup sets older than the given time. Old backup sets will not be deleted if backup sets newer than time depend on them. See the TIME FORMATS section for more information. Note, this action cannot be combined with backup or other actions, such as cleanup. Note also that --force will be needed to delete the files instead of just listing them.
The documentation of
target_url are a bit large to include in here. However, here is a summary of their description available from error message.
The acceptible [sic] time strings are intervals (like "3D64s"), w3-datetime strings, like "2002-04-26T04:22:01-07:00" (strings like "2002-04-26T04:22:01" are also acceptable - duplicity will use the current time zone), or ordinary dates like 2/4/1997 or 2001-04-23 (various combinations are acceptable, but the month always precedes the day).
Bad URL '/home/dan/deja-dup/'.
Examples of URL strings are "scp://firstname.lastname@example.org:1234/path" and "file:///usr/local". See the man page for more information.
So as an example, to clean backups older than than the 1st of February 2016 in the ~/deja-dup directory, you can use the following command:
duplicity remove-older-than 2016-02-01 file:///home/$USER/deja-dup/
Note: This may not delete them directly if some of the matched backup are full backups that subsequent incremental backups may depend on them.
Also, according to the manual, this would only list the files that will be deleted. You will need to append the command with
--force for the files to be deleted.
Déjà Dup uses
duplicity as its backend (This means that it is basically a User Interface for