EBS volumes should be in a backup plan

How to fix it

Assign the volume to an AWS Backup plan: add a resource assignment on a plan in the same Region naming the volume's ARN, a wildcard covering it, or its tags. It passes on the next scan, without waiting for the first backup to run. Snapshots you take by hand, and Data Lifecycle Manager snapshots, are not AWS Backup and do not count. Where the Region is not opted in to AWS Backup for EBS, an assignment that does not name volumes (the ARN, or arn:aws:ec2:*:*:volume/*) counts only if the instance the volume is attached to is in a backup plan. Only in-use volumes are evaluated.

In the console

AWS Backup → Backup plans → the plan → Resource assignments → Assign resources

With the AWS CLI

aws backup create-backup-selection --backup-plan-id <backup-plan-id> --backup-selection '{"SelectionName":"ebs-volumes","IamRoleArn":"<backup-role-arn>","Resources":["arn:aws:ec2:*:*:volume/*"]}' --region <region>

With Terraform

resource "aws_backup_selection" "this" {
  name         = "ebs-volumes"
  plan_id      = var.backup_plan_id
  iam_role_arn = var.backup_role_arn
  resources    = ["arn:aws:ec2:*:*:volume/*"]
}