|I would have to agree with ijack.|
If you don't have a spare PC, spend the money and buy a NAS enclosure that provides redundancy by utilizing RAID technology and two or more hard drives.
I have a small 2 drive NAS at home that is running the two hdd's in a RAID 1 configuration. Should one of my two drives fail, I simply replace it, tell the RAID to rebuild and I never lose a beat, or any data. If you can afford it, a NAS device, or a PS with a RAID capable controller is your best bet.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.