You must activate the Alibaba Cloud Elastic Compute Service (ECS) Snapshot service before you can create snapshots.
Background information
You are not charged for activating the ECS Snapshot service. After you create snapshots, you are charged for the snapshots based on their size and storage duration by default. Hourly bills are generated on the hour per region. Keep an eye on your snapshot size and snapshot fees. We recommend that you delete unneeded snapshots on a regular basis or purchase Storage capacity units to offset snapshot fees. For more information about snapshot billing, see Snapshots.