I currently have so many frickin photos that I use an external portable hard drive for them. It's a Western Digital with a USB 2.0 connection. It is my only source of my entire photo album at the moment. What is the best way to back it up? Plug in another external HDD so both are using the USB-A ports on my MacBook and try to clone it? Or should I plug them both in and then do a massive Copy/Paste from one drive to the other? I'd like to keep the back up updated on a fairly regular basis. Thanks!