Cloning RAID 1 drive to RAID 0

A single drive (the 278GB) cannot be a RAID by itself. A raid 0 array requires atleat 2 drives so i assume that that is a Raid 0 of two 138GB drives
If i understand correctly, there are 4 physical drives (138 gb each). 2 are mirrored (RAID 1) and the other two are stripped (RAID 0).
I believe you cannot mirror a Raid1 array on a Raid 0 array. From what you are trying to do, i assume that you are trying to ensure maximun data secutiry.

Your best bet would be to create a raid 1 array with 4 drives. That means that all 4 drives contain the same data and the system can work with 3 of the 4 drives failing.
I dont see the point of mirroring a mirrored array (nor the benefits of that).
If you managed to mirror it on the RAID 0 Then there are 3 copy of the data and a maximum capasity of 138gb (which is that of the smallest drive). Therefor 138gb are lost. If you create a RAID 1 array across 4 drives then you have 4 copies of the same data and the same maximum capacity.

Thanks for your reply. I didnt really give enough info.

This is my setup.

OS Drive is 2 138gb drives - RAID 1
Data Drive is 2 278gb drives - RAID 1

Spare drive is 278gb that apparently is RAID 0 judging by the screen dump below



What would you recommend on this? Add the spare drive to the OS RAID 1? A hot spare?