Files are not deleted from the archive on schedule


2 folders (A_back_files and B_back_files). Backups are copied to these folders every day, and backups older than 27 days are deleted.
The duplicate has 1 configured task - copy these files to the cloud, but:
Files from folder A are added and deleted every 5 days;
Files from folder B are added but not deleted every 5 days.

Why it happens?

Welcome to the forum!

I’m not sure I fully understand your scenario. Duplicati will never delete files from the source folders. The files in the target folder may stay there longer than the backup retention. This is because of how Duplicati works. It uses deduplication to break files into chunks, and only stores each chunk one time in the back end target location.

Let’s say you run daily backups and started on Jan 1 2019. Backup retention is set to 1 month. If at least some of your data stayed the same from the Jan 1 2019 backup, then it is very likely you will still see duplicati backup files dated Jan 1 2019 on the back end when you look at it today, in December, even though your retention is 1 month.

You can confirm that your retention is working by starting a Restore process and looking at the dropdown where you select the backup time. If retention is set to 1 month, you shouldn’t see anything older than 1 month.

Thanks for the comment.
Folders A_back_files and B_back_files back up files every day. Once a week, they are copied to an external drive.
Duplicati uploads these copies (A_back_files and B_back_files) to the cloud, in case the server crashes within a week.

Application log:

Source Files
Examined 22 (29.83 GB)
Opened 2 (3.76 GB)
Added 2 (3.76 GB)
Modified 0 (0 bytes)
Deleted 1

and so every day

Your log doesn’t necessarily show any problem. Duplicati is telling you of the changes it saw to the source files since the last time it was run: 2 files were added, 1 was deleted, etc.

If you look at the complete log, backend statistics section, you can see how many changes were made on the back end:

    "BackendStatistics": {
      "RemoteCalls": 260,
      "BytesUploaded": 6547307283,
      "BytesDownloaded": 52368487,
      "FilesUploaded": 255,
      "FilesDownloaded": 3,
      "FilesDeleted": 0,

Remember - Duplicati is not a file synchronization tool. It’s a backup tool that uses deduplication. There will no be a 1-to-1 relationship between files added on the source side and files added on the backend side.