Which solution will meet these requirements?
Set the DeletionPolicy attribute to Snapshot for the EC2 instance resource in the CloudFormation template.
Automate backups by using Amazon Data Lifecycle Manager (Amazon DLM).
Create a backup plan in AWS Backup.
Set the DeletionPolicy attribute to Retain for the EC2 instance resource in the CloudFormation template.
Explanations:
Setting the DeletionPolicy attribute to Snapshot creates a snapshot of the EC2 instance, which preserves the data. However, this does not retain the instance itself, meaning the instance will be terminated, and only the snapshot will be created. This does not meet the requirement to keep the instance.
Automating backups using Amazon Data Lifecycle Manager (DLM) manages the lifecycle of snapshots but does not ensure that the EC2 instances themselves are retained if the CloudFormation stack is deleted. DLM is more about managing snapshots than preserving instances.
Creating a backup plan in AWS Backup allows for managing backups across AWS services, but like DLM, it does not directly address the requirement of retaining the EC2 instance if the stack is deleted. AWS Backup is used for data protection but does not retain the instances themselves in a CloudFormation context.
Setting the DeletionPolicy attribute to Retain ensures that the EC2 instance is not deleted when the CloudFormation stack is deleted. This meets the requirement of keeping both the instances and their data intact, as the instances will remain in the account even after stack deletion.
In my experience, the answer is:
Set the DeletionPolicy attribute to Retain for the EC2 instance resource in the CloudFormation template.