For about 8 years now I have tried to use Freenas with USB hdd docking stations. I remember years ago Cyberjock telling me not to use USB and I decided personally that it should work. It didn't. I have literally spent about 8 years trying to keep a USB Freenas system going. For a long time USB 2.0 worked "ok", but they would still drop alot and I would have to resilver arrays. Just recently I tried upgrading to USB 3.0 with USB 3.0 docking stations and I have already had to resilver disks about 10 times. The disks just constantly get errors. I have tried using different computers and power supplies and everything else I can think of. It just doesn't work. I don't know what it is between USB and ZFS but they just don't work together. I finally broke down tonight and ordered some eSata bays. I am making this post in the hopes that if anyone wants to use USB for Freenas that they won't. Don't do it, it just doesn't work. I have tried, trust me.