I bought too many 8TB easystores when they were on sale and I've decided that I want to use the ones that wont fit in my case as backup drives. Just USB attached and sitting on top of the case. What I want to do however is make sure that in those 5 drives there is at least 1 copy of every file. If there's a fire or emergency or whatnot, I want to be able to grab the 5 externals sitting on top and be confidant that I have a full copy of everything (assuming working hardware). I know that at one point there was a feature that was similar to this but it didn't quite do this. Additionally i would ideally like all file access to NOT come from these USB drives, both for speed and wear on the drives.
My current setup (by accident due to a migration) is my main pool and a pool of 5 8TB drives that has a complete copy of the data. I know it would be easy to just set a scheduled task to backup to that pool, but I didn't know if there was a more elegant solution built in.