used the seagate NAS 8 TB on sale from Amazon. Directions were perfect; reformatted and up and running; time around 1.5 hours because my trimming wasn't good enough the first time and the drive didn't sit down far enough for the metal plate/torx screws to go on nicely; slight re-do but everything worked great. PS. Pair of long nosed pliers worked well to remove and re-place the rubber pads at the bottom of the cavity for the hard drive.