EC2 AMI Flashcards
What is an Amazon Machine Image (AMI)?
An AMI is a template that contains the software configuration (operating system, application server, and applications) needed to launch an EC2 instance. It ensures instances can be rapidly deployed with pre-configured settings.
How are AMIs categorized?
AMIs are categorized into public AMIs, which are available to all AWS users, and private AMIs, which are only available to your AWS account and those you explicitly share the AMI with.
What components make up an AMI?
An AMI includes one or more EBS snapshots or, for instance-store-backed instances, a template stored in Amazon S3. It also includes launch permissions and a block device mapping that specifies the volumes to attach to the instance upon launch.
How does one create an AMI?
You can create an AMI from an existing EC2 instance by using the AWS Management Console, AWS CLI, or SDKs. The process involves specifying the instance and configuring details like no-reboot options and block device mappings.
What are the benefits of using pre-configured AMIs?
Pre-configured AMIs save time and provide consistency by allowing users to launch instances with a known configuration, reducing the setup and configuration time for new instances.
How can you share an AMI with other AWS accounts?
You can share an AMI with other AWS accounts by adjusting the AMI’s launch permissions to include the AWS account IDs of the accounts you wish to share with. You can also make an AMI public, making it available to all AWS users.
What considerations should be taken into account when choosing an AMI?
When choosing an AMI, consider factors such as the operating system and version, CPU and memory requirements, compliance and security requirements, and whether you prefer to use a pre-configured AMI from AWS, a third-party, or to create your own.
Can AMIs be copied between regions?
Yes, AMIs can be copied between regions using the AWS Management Console, AWS CLI, or SDKs. This feature is useful for deploying applications consistently across different geographic locations.
What is the role of AMIs in Auto Scaling?
AMIs play a crucial role in Auto Scaling by ensuring that all instances launched as part of an Auto Scaling group have the same configuration, software, and setup, facilitating horizontal scaling.
How do you manage AMI storage costs?
Manage AMI storage costs by regularly auditing your AMIs and associated snapshots, deleting old or unused AMIs and snapshots. Remember, AMIs for EC2 instances backed by EBS snapshots incur storage costs.
