A couple of questions:
- Which drive did you select, and what disk format does it use?
- Did the other drive work?
The Backup function in Roon is solely for the Roon database; there is no built-in backup function for the music files themselves.
There is a feature request for this , but nothing has been announced by Roon Labs thus far.
Most of us are using third-party solutions to backup the music files over the network