What is an AMI?

• An Amazon Machine Image (AMI) is like a snapshot of an EC2 instance that contains the operating system, software, and configurations. It’s what AWS uses to create new instances with your settings ready to go.

Why Use an AMI?

• It saves time when launching new instances since you don’t have to install and configure everything from scratch.
• It ensures consistency across instances, so they all have the same setup.

Key Things to Know

1. Customizable: You can create your own AMI from an existing instance that you’ve configured just the way you want.
2. Pre-Built Options: AWS offers many pre-made AMIs with different operating systems (like Windows or Linux) and pre-installed software.
3. Used in Auto Scaling: Auto Scaling launches new instances from an AMI, so each new instance has the same software and setup.

When to Use AMIs

• Scaling Quickly: If you need to launch multiple instances, AMIs let you set them up in seconds with everything pre-configured.
• Cloning Servers: Use an AMI to replicate an instance for testing, backup, or deployment in another region.

Best Practices

• Keep AMIs Updated: Make sure your AMIs have the latest software and security patches.
• Delete Old AMIs: Remove outdated AMIs to save storage and avoid clutter.
• Use Tags: Label your AMIs so you know what’s inside and where it’s used.