I recently went on an upgrade crusade to my homelab, and as part of that, upgraded FreeNAS to 9.3. When I did, there was a non-urgent alert about a driver mismatch for my LSI HBA (FreeNAS expected 16, LSI had 12). Thus, I decided to upgrade the firmware. Directions This assumes that your server can boot directly into an EFI shell. It might require a Shell.efi for some motherboards, but I can't tell you much more than that, as it boots straight to EFI on mine.