I have a 36T NAS (26T usable raidz2), built using the Norco 4224 chassis. The backplane / drive trays that it comes with aren't 100% reliable, so I would recommend trying to get a SuperMicro chassis instead. I keep mine in the attic to keep the noise down. Mine runs fine on an old Q6600 with 4G of RAM. I'm not trying to do anything silly, like enabling dedupe, so it's not a problem. I'm running ZFS on Linux, again, n…
I've been using crashplan on my NAS for a few years now, but I feel bad and only really backup critical stuff. (aka its just a few TB) rather than the full 50T+ on the NAS.