Power went out during defrag, no space left

ahkjeldsen wrote:
I kinda thought the whole "RAID" thing would take care of when drives died, like giving me a chance to replace the single drive that died. I'm have two WD Red 4 TBs in my NAS and they should be pretty durable - hence I'd be pretty unlucky if they both died at the same time, right?

There are other failure modes (for instance NAS chassis, lightening/power surge) which could corrupt/destroy data - not to mention theft/fire/flood.

Also, there are many posters here who had a second drive die while waiting for the first replacement to arrive. So it isn't as unusual as you might think. After all, the drives are identical, are in the same chassis, and (thx to the mirroring) have exactly the same usage pattern.

So RAID is useful, but not a substitute for backup.