Another RAID level migration question

I have an array on two drives which was set up as a RAID-0, because I needed the space and performance. Now I have another identical drive, ideally I would like to get to RAID-5, but I don't think that is going to fly, so how about RAID-4? I could create with a missing parity drive, then add the drive and see if it will rebuild.

I hope to test this using loop devices, but time is fairly short right now.

-- 
bill davidsen [off-list ref]
 CTO TMR Associates, Inc
 Doing interesting things with small computers since 1979