Python script to generate stats about backend storage

Thanks! That must have taken some learning of DB tables. Feel free to keep on learning…

backup-test-samples and a new option below can adjust that to leave fewer gaps, if you like:

  --backup-test-percentage (Integer): The percentage of samples to test after a backup
    After a backup is completed, some (dblock, dindex, dlist) files from the remote backend are selected for
    verification. Use this option to specify the percentage (between 0 and 100) of files to test. If the
    backup-test-samples option is also provided, the number of samples tested is the maximum implied by the two
    options. If the no-backend-verification option is provided, no remote files are verified.
    * default value: 0

Add backup-test-percentage in addition to backup-test-samples [$25] #3296 inspired the above, noting:

Checking only 1 sample per backup when there are thousands of files doesn’t make much of a dent

Backup Test block selection logic describes sampling algorithm. I hope that its approach makes sense.

upload-verification-file and the DuplicatiVerify utility-scripts can do major verification if file access exists.

The COMPACT command describes some tuning, if the default options for compact are not as desired.
Using verbose log level or capturing with log-file-log-filter are other ways of getting stats about compact.