Chapter 7.7 - Amazon Machine Images: EBS vs. Instance Store

Question 1

What is an AMI?

Answer 1

An Amazon Machine Image (AMI) provides the information requires to launch an instance.

An AMI is just a blueprint for an EC2 instance.

You must specify an AMI when you launch an instance.

Question 2

What are the 5 Things You Can Base You’re AMI On?

Answer 2

Region

Operating system

Architecture (32-bit or 64-bit)

Launch permissions

Storage for the root device (root device volume)

Question 3

What is the difference between a root device for an instance launched from the AMI on EBS vs Instance Store?

Answer 3

Amazon EBS

• The root device for an instance launched from the AMI is an Amazon EBS volume created from an Amazon EBS snapshot.
• EBS-backed instances can be stopped.

Instance Store

• The root device for an instance launched from the AMI is an instance store volume created from a template stored in Amazon S3.
• Instance store volumes cannot be stopped.

Both

• You can reboot both EBS and instance store volumes and will not lose your data.
• By default, both root volume types will be deleted on termination. However, with EBS volumes, you can tell AWS to keep the root device volume.