Elastic Compute Service：CreateSnapshot

The local snapshot feature is replaced by the instant access feature. Take note of the following items:

• If you have used the local snapshot feature before December 14, 2020, you can use Category.
• If you have not used the local snapshot feature before December 14, 2020, new snapshots of your Enterprise SSD (ESSD) series disks are instantly available after creation without the need for additional configurations, regardless of whether the snapshots are manually or automatically created. ESSD-series disks include ESSDs, ESSD AutoPL disks, ESSD Entry disks, and Regional ESSDs. InstantAccess, InstantAccessRetentionDays, and DisableInstantAccess that are related to the instant access feature no longer take effect in API operations. Available is added to the DescribeSnapshots and DescribeSnapshotGroups operations to indicate whether snapshots are available.

Prerequisites:

• Elastic Compute Service (ECS) Snapshot is activated. For more information, see Activate ECS Snapshot.

• The disk for which you want to create a snapshot is in the In_use or Available state. Take note of the following items:

  • If the disk is in the In_use state, make sure that the ECS instance to which the disk is attached is in the Running or Stopped state.
  • If the disk is in the Available state, make sure that the disk was attached to an ECS instance. Snapshots cannot be created for disks that have never been attached to an ECS instance.
  • When you use a disk to create a dynamic extended volume or a RAID array, we recommend that you create a snapshot-consistent group and enable the application-consistent snapshot feature to back up data. When a business system involves multiple disks, you can create a snapshot-consistent group to ensure a consistent write order and the crash consistency of business system data. For more information, see Create a snapshot-consistent group and Create application-consistent snapshots.

In the following scenarios, you cannot create snapshots for a disk:

• The number of manual snapshots of the disk has reached 256.
• A snapshot is being created for the disk.
• If the response contains {"OperationLocks": {"LockReason" : "security"}} when you query information about an ECS instance, the instance is locked for security reasons and no operations are allowed on the instance.

When you create a snapshot, take note of the following items:

• We recommend that you create snapshots during off-peak hours because snapshot creation degrades disk I/O performance by up to 10% and slows down data reads and writes.
• If a snapshot is being created, you cannot use this snapshot to create a custom image by calling the CreateImage operation.
• If operations are performed on the disk and incremental data is generated when a snapshot is being created, the incremental data is not included in the snapshot.
• When a snapshot is being created for a disk that is attached to an ECS instance, do not perform operations that change the status of the instance, such as stopping or restarting the instance. Otherwise, the snapshot may fail to be created.
• You cannot resize a disk for which a snapshot is being created. Wait until the snapshot is created before you resize the disk.
• After you create snapshots, you are charged snapshot storage fees per region based on the total size of the snapshots that are stored in the region. For more information, see Snapshots .
• You can create snapshots for a disk that is in the Expired (Expired) state. If the release time scheduled for a disk arrives while a snapshot is being created for the disk, the snapshot is in the Creating (Creating state and is deleted when the disk is released.