I understand the philosophy behind not saving until validated, but there are many examples in software where this is not true. For instance, setting up a mail account in Thunderbird or outlook. You can use the wrong settings on initial setup (indeed, outlook forces you to in some circumstances) then go repair them later. This also solves the second issue I raised in #1624 because running backup.py --validate will try to use the new settings, just like the Unkown Error case error message implies it should.
The elif needed to check to see if the string was in the listing of results of the shell command. As it was the conditional was just the string which always evaluates to true and was therefore giving a misleading error message.
captainwasabi