 <p>It depends on the type of instance. If it's EBS backed you are probably safe to proceed as the volume will be reattached. If it's instance store backed and you lost access to it you basically have lost what's on that machine.</p> <p>By the sounds of it it's EBS backed. If it's instance store backed and you later created and attached an EBS volume and used that, you're going to be able to restore/reattach that volume just fine - but it's going to be to another machine. </p>