Amazon Machine Image (AMI)

  • An Amazon Machine Image (AMI) provides the information required to launch an instance.​
  • AMI comes with various base images Amazon Linux, Ubuntu, Fedora, Red Hat, Windows etc.​
  • These images can be customized at runtime using EC2 user-data​
  • AMI allows you to create your own customized image.
  • AMI Includes – One or more EBS snapshots for instance-store-backed AMIs, a template for the root volume of the instance (for example, an operating system, an application server, and applications).​
  • You can launch multiple instances from a single AMI when you need multiple instances with the same configuration.​

AMI uses S3 for storing

  • When you create your own AMI from the instance it requires space to store and they live in Amazon S3​.
  • Hence you are charged for the space occupied in S3 for storing S3. So make sure you remove the AMIs which are not in use.
  • By default AMIs are private and locked for your account/region​. They can be made public and shared with other AWS accounts if required.

Shared AMI behavior

  • You can share an AMI with another AWS account.​
  • Sharing an AMI does not affect the ownership of the AMI.​
  • You cannot associate your billing product shared by other while again sharing the AMIs to public
  • You can share an AMI with specific AWS accounts without making the AMI public. All you need is the AWS account IDs.​

Benefits of using AMI

  • AMIs comes with pre-installed OS and other packages
  • When you use AMI to create instance you don’t need to use user-data for startup automation every time
  • Helps in deploying set of instances in one go faster than manually creating EC2 instances
  • Public AMIs help you reduce time in commissioning instances

You cannot use ADDS in AMIs as replicating the DC with same domain in multiple locations will be of no use.