Why does my Amazon EBS snapshot show no progress or shows the error, "ConcurrentSnapshotLimitExceeded"?

Short description

The ConcurrentSnapshotLimitExceeded means that you reached the limit on the number of concurrent snapshots that you can create on a specific volume.

The error can occur for the following reasons:

• You have too many snapshots running concurrently. 
• You delete an in-progress snapshot. If you initiate a new snapshot after deleting an in-progress snapshot, then the displayed progress percentage might be stuck for an extended period of time. The deleted snapshot progress continues until it's 100% complete.
• You try to initiate more than the allowed concurrently pending snapshots, including in-progress snapshots that you deleted.
• You create an Amazon Machine Image (AMI) and a new snapshot at the same time.

Note: Amazon Data Lifecycle Manager automates the creation, retention, and deletion of snapshots. Because newer snapshots capture data only after the previous snapshot, Amazon Data Lifecycle Manager can create snapshots more frequently and reduce the creation time. For more information, see Amazon Data Lifecycle Manager.

Resolution

When multiple snapshots run concurrently, newer snapshots remain pending until the pending snapshot with the oldest "Started" time moves to the Completed state. A single gp2, gp3, io1, io2, or magnetic volume can have up to five concurrent pending snapshots. A single st1 or sc1 volume can have one pending snapshot. Wait until the snapshots that are in the Pending state are complete. After all pending requests complete, check that you don't have snapshots that are in an Incomplete state, such as error. Snapshots in an Incomplete state count against your concurrent snapshot limit.

When you create an AMI for an instance, the AMI includes a snapshot of the volumes that are attached to the instance. When you create a snapshot during AMI creation, the snapshot might not show any progress until the AMI creation completes. To resolve this issue, wait for the AMI creation to complete before you create a snapshot.

Note: As a best practice, allow sufficient time for the previous snapshot to complete. For additional information, see Amazon EBS FAQs.

Related information

Create Amazon EBS snapshots

CreateSnapshot

Error codes for the Amazon EC2 API