I have never done that before but I imagine no, you are not supposed to have access to the operating system and know where the instance is. Similar to SNS and SQS, you don't get an IP of your SQS. I could set up an EC2 instance with some storage, but that goes back to my current design. If you do get that IP :-) contact AWS. That's probably a million dollar vulnerability. I'd suppose underneath they run container/lxc! Also, sadly, EFS is only available in us-west oregon :|