Can I convert S3 backed AMI to EBS backed AMI?

Question

Can I convert S3 backed AMI to EBS backed AMI? If yes, how? Can I convert EBS backed AMI to S3 backed AMI? If yes, how?

Answer 1

When an Amazon EC2 instance is started, the contents of the chosen Amazon Machine Image (AMI) are copied to the boot disk. This boot disk can be either:

• EBS-Backed, meaning the boot volume is created on an EBS volume (that persists even when the instance is stopped), or
• Instance Store-Backed (aka S3-backed because the AMI is kept in Amazon S3), meaning that the AMI is copied to the Instance Store (aka Ephemeral disk), which is lost when the instance is stopped.

In the early days of EC2, only Instance Store was available. These days, EBS is the preferred storage medium. The only benefit of using Instance Store-Backed AMIs these days is that it's cheaper (no charge for EBS), but the instances can't be stopped and the data on the disk is lost when the machine stops.

Here's some links to instructions for converting between the types:

• StackOverflow: Amazon EC2 - Convert EBS root device with instance store root device
• StackOverflow: Amazon EC2 - Swap root instance store device with EBS device
• AWS Blog: Converting an S3-Backed Windows AMI to an EBS-Backed AMI