the hopper will not recognize a 4tb drive, seems 2 4tb drives for sure will not work.
there is a way to backup movies and shows, in linux, (just did this a few weeks ago, on a 4tb drive that wasn't recognized)
i have seen superblock issues with dish 722k and earlier, and this time the hopper 3 moved my stuff to a lost&found folder, i had to move it back.
everything is working and nothing was lost.
could do a backup regiment, weekly, or whatever for archived shows and movies, then if the crap hits, restore the data. (unplug drive from the hopper, plug into computer, run imaging software, bring back to the hopper. )
ext4 i believe it is and linux is fun with permissions,