I’m currently running mine on Windows and use SnapRAID and DrivePool as my defense against drive failures. I think I have 7 data drives and 2 parity at this point. Beyond that I copy the Snapraid whatchamacallit to a separate backup drive along with my OS drive. This isn’t really a ‘backup’ but in the scenario where I have several failures and no way to restore, I still have radarr/sonarr keeping track of my library and a membership to several private trackers. I wouldn’t worry too much about losing media files as most can just be downloaded again. I find it more beneficial to make use of all the storage space you can rather than trying to do a 1:1 backup, which gets pretty absurd once you start getting up there in movie/TV count.