I understand. I’d be willing to let Duplicati run a costly analysis to find out. In other words I’d be willing to click a button “Analyze” and wait a long time to get the results.
I’d like to implement a backup scheme where I do daily backups, keep 3 days, then 1 backup per week for 10 weeks, then 1 backup per month for 12 months, then forever every 6 month. If I want to achieve something like that I need both the ability to delete at will (seems to be available through the command line) as well as information about space usage.
Not exactly an answer to your question, but maybe this helps:
You can see the increase in storage size between any 2 backup versions with the compare command.
From the Web UI, click to expand your backup job and click Commandline under “Advanced”.
Choose the command compare in the drop down menu.
Delete the contents of the “Commandline arguments” text box, replace it with “12”, “5” and “--full-result” (each value on a separate line, omit the double quotes).
Click the button Run “compare” command now at the bottom of the form.
This will list the difference between backup version 12 and version 5. It also returns the backup size of both versions.
Option --full-result lists all added, modified and deleted files, otherwise only the first 10 files are listed.
The compare command can be useful to track down which backup uploaded a lot of data and thus allocated much storage space.
Note that deleting a backup version that added much data to your remote storage does not mean that all storage space is reclaimed, as explained by @Pectojin.
If you accidentlly backed up one or more large files or folders and want to delete them from every backup set, you can do this using the purge command.
Don’t forget to delete or move the files to a location outside the selection of your source files, otherwise they will be uploaded again the next time the backup runs.
Another option is to exclude these files from your source files selection.
You can delete a specific backup version using the --version=n option. The easiest way to do this, is invoking the Commandline form in the Web UI, just like the compare command above.
Duplicati’s native Command Line exe does not integrate with the normal Web UI engine at all. For such integration I always recommend the excellent duplicati-client command-line utility.
With it you’d do something like:
.\duplicati_client.exe login
.\duplicati_client.exe list backups
.\duplicati_client.exe logout
You can also trigger backup jobs using this utility, among many other useful things…
I want to delete some old versions. I want to achieve something like a “grandfather father son” scheme with monthly forever, a few weekly and a few daily. I want manual control over what backup versions to keep.
For true command line (not the GUI one), do the same thing, starting with Export As Command-line.
Note that version 0 is the latest, so make sure a scheduled backup doesn’t run while you’re planning what to delete, because all of your numbers might shift… Actual delete will need the –version option.
EDIT: while there are sizes, these are probably not exactly the concept of size that you have in mind:
The FIND command says what should be happening. Feel free to file an Issue for a developer to look:
--include=<string>
Reduces the list of files in a backup to those that match the provided string. This is applied before the search is executed.
--exclude=<string>
Removes matching files from the list of files in a backup. This is applied before the search is executed.
OK, I understand. It seems that it would be better to have a separate command that lists the versions. Overloading the find command with these two unrelated modes does not seem very usable.