[smhinsey]

Do you mean RAIDing local instance storage? I haven't heard of this approach so far, do you have any links?

[blantonl]

Depending on the instance that you have provisioned, you have anywhere from 1 to 4 ephemeral (local) disks available to your instance.

They are typically available as /dev/sd[bcde]

In centOS, implementing a RAID-0 block device across 2 ephemeral disks that is present on an m1.large instance can be done via the following:

mdadm --create /dev/md0 --metadata=1.1 --level=0 --quiet --run -c 256 -n 2 /dev/sdb /dev/sdc

You'll then need to format the block device with your fs of choice. Then mount it from there.

[count]

Just remember the super important keyword:

ephemeral

WHEN your EC2 node disappears (and it will), you will lose everything on that RAID.

That's not a bad thing if you know it'll happen and plan for it, but do be aware of it.