RAID0 ephemeral storage on AWS EC2

If you're thinking of doing RAID0 (disk striping) on the ephemeral storage disks attached to an EC2 instance, this post is for you. First I'll go through some directions since I didn't find great ones elsewhere when trying to do it myself. Then I'll get to why I wanted to do it in the first place. When you run your instances, you have to add the extra drives in the block device mapping or they wil