Hi @TomEand @notoryous!
I'm sorry I haven't replied but here it comes:
I played around with my Unraid server in 2019 but the only good solution to make a complete backup back then was Duplicati. I wasn't easy to understand but I had a GUI.
I didn't get the backup to run perfectly and the speed was very slow when copying to a USB3 harddrive.
In the end I closed down my Unraid server and returned to the Synology system. I've been running a DS918+ since 2019 and upgraded to a Ds220+ as a main NAS for plex, Unifi docker, 3 cameras with Synology Surveillance System and files server for 4 macbooks and a Mac mini. I've created automated backup to a DS215+ and everything is running great.