I have multiple backups and most of them show somewhat similar size between source and destination.
For example photos show 1.6TB source and 1.42TB destination / 8 versions
Data (documents) show 390GB source and 268GB destination / 6 versions
However a backup that is mainly large video files, with some smaller video editing project files shows:
source 1.6TB vs destination 141 / 1 version
These files are not duplicates, each video has been recorded at different location and has different content. I am worried something is wrong - any quick test other than running the whole restore to a different drive via the internet?
Only 141 without any unit? You can get an idea in bytes of what Duplicati thinks is there in the log files’s Complete log → BackendStatistics → KnownFileSize. Other stats may help, or look at the destination.
Commandline with the default backup command changed to find should give some info at version level after you empty the Commandline arguments box. It should show the size of all your versions (so one).
Putting a * in the box should show all the files with their sizes, so you can see if the answer is plausible.
These are fast results from the local database. There’s no substitute for doing some actual restore test, although after you’ve sanity-tested with the above, you might feel comfortable with just restore samples.
Advanced option no-local-blocks should be set for most reliable result. It forces restore from destination.