on a HVM instance /dev/sda1 remaps to /dev/xvda. But then if you attempt to attach to /dev/xvda directly, then you would have your EBS in attaching state
on a HVM instance /dev/sda1 remaps to /dev/xvda. But then if you attempt to attach to /dev/xvda directly, then you would have your EBS in attaching state