I've burnt through my 3rd SD card, and this is getting annoying (not to mention slightly costly). Obviously having a 24-hour running (actually running, not idle) pi is going to lead to that, so I'm looking at using a Pi off the Hard Disc.
I'm okay with having an SD card in there, as long as it's just /boot, and everything else under / is on the hard disc. Is this possible on the Pi 2 B+, or do I need the Pi 3 (where can don't even need the SD card and can just boot off a USB disc)?