This step should be done before setting up Plone.

Use Elastic Fox to create a new Elastic Block Storage Volume.

Elastic Fox > Volumes and Snapshots > (+) button > 

Make 4GB and set the device to /dev/sdp (p for Plone :) )

On the instance do the following:

 mkfs.ext3 /dev/sdp (ONLY NECESSARY THE FIRST TIME)

 echo "/dev/sdp /opt ext3 noatime 0 0" >> /etc/fstab 

mount /opt

Now do the Plone Stuff:

either a Development Server or a Production/Hosting Server