I only have answers for 2 out of 4 questions. We’ll see if anyone else wants to try on the other questions:
The AFFECTED command could be fed the remote filename of concern.
looks like it’s just what’s returned if you got past “No files examined, is the remote destination is empty?” which is 100, and “Examined {0} files and found no errors” which is 0. It explains errors then returns a 3, which means the return code documentation isn’t quite right, or maybe the return code here isn’t right…
C:\Program Files\Duplicati 2>Duplicati.CommandLine.exe help returncodes
Duplicati reports the following return/exit codes:
0 - Success
1 - Successful operation, but no files were changed
2 - Successful operation, but with warnings
50 - Backup uploaded some files, but did not finish
100 - An error occurred
200 - Invalid commandline arguments found
C:\Program Files\Duplicati 2>
One experiment you could do, if you can figure out what’s potentially impacted by a file giving complaints, would be to try a file restore and see whether or not the restore will restore the source file properly or not. Restore to some other area of course, not directly on top of the original file which might make it incorrect.
Generally I would think “Extra” information is fairly harmless, but others sound worrisome, per the below:
The lead developer doesn’t answer as much here as before, but Google found several previous thoughts:
Verify a specific dblock.zip.aes file (specifically sounds pretty harmless)
Question about TEST command vs. Backup with –full-remote-verification and backup-test-samples (implicitly sounds pretty harmless, however with wrong guess at cause)
How to recover backup with damaged dblock file? (has thoughts, user tries lots of repairs, made it worse)
This is me jumping in with a technical deep dive plus guesses when I hit this one. That killed that topic. 