Thanks to all. I don't know about the format, I had a more 'computer saavy' friend do it...
house70: are you recommending not using a 3TB?
Not without a RAID 1 setup. That would require a second HDD of equal (or larger) capacity and an enclosure that supports RAID1.
They don't have to be fancy or anything. I use Synology for mine. I know you can build a network-attached-storage (NAS) system from scratch, but usually ends up more expensive than a plain 2-disk enclosure.
As I mentioned, in my experience
, the larger the HDD, the less reliable on a long run they are. Everyone's mileage may vary....