Thanks, I didn't fully understand the syntax before. I now see the volume in the duplicati GUI, but not its contents. When I just back up the entire volume, the backup size is basically zero (should be more like 800MB).
Thanks! A drop down chevron has appeared next to the "Source Data" folder in duplicati, but it is still empty, showing neither the volume, nor its contents. Any idea what else I can try/modify?
Sweet, were you able to fit the extra SSD inside the case?