@mngrif yep we had a bunch of 3TB drives (they were the flood-affected Seagates not WDs, I was wrong above). So we bought some pcie cards that gave enough sata ports, and got a giant desktop tower case that could hold it all. Not much to it.

If your disks are different sizes it's more complicated. Each vdev limits to the smallest disk size (wasting 3/4 of your 2tb disks). So you probably want 2 vdevs in a pool, disks allocated by size. Downside is you spend 2 parity disks per vdev not per pool.