File copy from RN528 to RN424 - which method is fastest?

Thanks StephenB .

So the Rsync setup - struggling... again:

- Main NAS is 192.168.1.80, Backup NAS is 192.168.1.82

- Creating a new backup job from the Backup NAS GUI per our earlier chats

- First (left-hand side), choose "Remote" (correct?)...  otherwise, when I choose "Local", I only see the Backup NAS folders

- Choose "remote: Rsync Server"

- Host:  type in the Main NAS IP  (xxx.xxx.x.80) per our earlier chat (instead of the NAS name)  -  is this correct? i.e., the Main NAS is the host?

- Port 873 is auto-populated

- Share:  When I click "Browse" I can only see the Main NAS "Pictures" share - why?  Cannot see "Documents" or other shares on the Main NAS.  The "Pictures" share is mapped in Windows (X:), so do I have to map every share to a drive letter for it to be visible in this backup tool? Doesn't sound right. When I manually type in "Documents", the "Test Connection" returns an error. When I manually type in "Pictures", the "Test Connection" works. So I'm stuck. I don't know how to convince this archaic tool to add the share I want to backup.

This is what I meant earlier about not liking this tool. It's not intuitive at all. Previously, the only way I could get backups to work at all was by programming them from the Main NAS, where I could see the shares I wanted to backup.