Originally Posted by nleksan
Use 4 in a RAID10 array, and spend the remaining money on an external drive that's as close to or ideally the same size as the array.
Then backup critical data or the entire array once a week or so, and the rest of the time leave the external drive unplugged from everything and ideally in another place.
You cannot prevent drives from failing, but you can minimize the potential losses as much as possible. RAID10 can sustain UP TO 2 drive failures before total data loss, gives you the write speed of 2x one of the drives, and the read speed of all 4. It also has no parity calculations (stripe of mirrors) so you can do it with your on board RAID easily and without the massive write penalties you get from 5/6, not to mention the low CPU overhead.
4x2TB drives in RAID10 + 1x4TB external eSATA or USB 3.0 drive is ideal, IMHO.
Thats quite overkill i think, i dont store that much sensitive data, it would suck a lot to lose them, but i wont lose money or somehting like that. I like a collector.