title: (AWS/EC2/EBS) Why does "Delete on Termination" default to true for root devices?
body: <p>On Amazon EC2, when you use an EBS volume as the root device for an EC2 instance, the "Delete on Termination" flag defaults to true, meaning the volume will automatically be deleted when you destroy the instance.</p>
  
  <p>What is the point of this?</p>
  
  <p>If the primary benefit of using EBS over local instance storage is storage persistence independent of instance persistence, doesn't this completely defeat the purpose of that?</p>
  
  <p>If you don't mind the root device being destroyed along with the instance, why not just use local instance storage which is cheaper and less effort to create/manage?</p>
  
  <p>Relevant references:</p>
  
  <ul>
  <li><a href="http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/RootDeviceStorage.html" rel="noreferrer">http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/RootDeviceStorage.html</a></li>
  <li><a href="http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ComponentsAMIs.html#storage-for-the-root-device" rel="noreferrer">http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ComponentsAMIs.html#storage-for-the-root-device</a></li>
  <li><a href="http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-lifecycle.html#lifecycle-differences" rel="noreferrer">http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-lifecycle.html#lifecycle-differences</a></li>
  </ul>