Not entirely clear on your question, however as your title is "RAID 0 backup"
There are a number of different RAID configurations that provide redundancy, however RAID 0 (Striping) is not one of them.
If you lose one disk in the RAID 0 set, then you lose the data on the RAID set. RAID 0 is purely used to improve performance, by increasing the number of disk heads performing read and write actions.
If the data is critical, you may want to use RAID 1 (Mirroring) This doesn't give you the improved performance that you get in RAID 0, however it gives you improved stability by reducing the impact of a single disk failure.
You may want to check out the following for further information: