I have installed the online back-up plugin demonstrated in this video
And I ran the back-up. It failed with the following message
The backup failed: The backup is larger than your complete quota on the online vault. It cannot be stored. Please reduce the backup size by excluding something - it is currently 200.06 MiB in size. Please consult the event log for more information.
I only performed this back-up because it was recommended when I went to update to 3.3.1