Does Duplicati verify the backend content at each backup?

Is there a check that all the files that are supposed to be on the backend are really there? Is it done by default after each back up? or should we do it manually?
There is an option --list-verify-uploads = false Verify uploads by listing contents. By default it is false, it means no verification is done on the list by default? Or is this option only for the files that have been just updated?

According to the comment in the code, --list-verify-uploads tells Duplicati to verify uploads by listing the contents of the destination folder:

A value indicating if server uploads are verified by listing the folder contents

Even though it defaults to false, if you’re concerned about it (e.g., due to a particular backend you’re using having a potential to lose data), you should be able to set that flag to true.

I believe Duplicati checks that the expected files are all present when starting a backup by default (I feel like I’ve had test backups complain because I changed or deleted files on the destination). It also has the --backup-test-samples and --backup-test-percentage options (default is 3 samples) to validate the content of the backend files. Though content validation requires downloading file contents, so full validation that way is likely to take a long time for large backups.

1 Like

Ok so “–list-verify-uploads = true” aims at checking that the NEW files are well listed on the backup after the uploads, right?
Knowing that in anycase the check will be done for ALL FILES at the next backup

Am I right?