CreateSnapshot

Original local snapshots have been replaced by snapshot instant access. The parameter descriptions are as follows:

• If you used local snapshots before December 14, 2020, you can use the Category parameter as usual.

• If you did not use local snapshots before December 14, 2020, no additional configuration is required. Snapshots created for enterprise SSD series disks (ESSD, ESSD AutoPL, ESSD Entry, and regional ESSD) have snapshot instant access enabled by default after creation, and both manual snapshot and automatic snapshot are supported. The InstantAccess, InstantAccessRetentionDays, and DisableInstantAccess parameters related to the snapshot instant access feature no longer take effect in API operations. The DescribeSnapshots and DescribeSnapshotGroups API operations add the Available response parameter to describe the available status of snapshots.

Before you begin:

• The snapshot feature is activated. For more information, see Activate snapshots.

• The disk must be in the In Use or Available state. Precautions for different states:

  • If the disk is in the In Use state, the instance must be in the Running or Stopped state.

  • If the disk is in the Available state, make sure that the disk has been attached to an ECS instance before. You cannot create snapshots for disks that have never been attached to an ECS instance.

  • When a disk is used to create a dynamic extended volume or a RAID array, we recommend that you use a snapshot-consistent group and enable application-consistent snapshots to back up data. A snapshot-consistent group ensures the chronological consistency of data written to disks and guarantees crash consistency in scenarios where a business system spans multiple disks. For more information, see Create a snapshot-consistent group and Create an application-consistent snapshot.

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

• Avoid creating snapshots during peak business hours. When a snapshot is being created, the disk I/O performance decreases by less than 10%, and the read and write performance may experience brief instantaneous slowdowns.

• If the snapshot creation is not complete, the snapshot cannot be used to create a custom image (CreateImage).

• Incremental data generated by disk operations during snapshot creation is not backed up to the snapshot.

• If the disk is attached to an ECS instance, do not change the instance status during snapshot creation, such as stopping or restarting the ECS instance. Otherwise, the snapshot creation fails.

• You cannot expand a disk for which a snapshot is being created. Wait until the snapshot is created before you expand the disk.

• You can create snapshots for disks in the Expired (Expired) state. If a disk reaches its expiration and release time while a snapshot is being created, the snapshot in the Creating (Creating) state is deleted when the disk is released.

• After a snapshot is created, the system bills you based on the snapshot size in each region. For more information, see Snapshot billing.

• You cannot create snapshots for a specified disk in the following scenarios:

  • The number of manual snapshots retained for the disk has reached the upper limit. For more information, see Snapshot limits.

  • There is a concurrency limit for creating snapshots. Exceeding the limit causes the creation to fail. For more information, see Snapshot limits.

  • When you query ECS instance information, if the response contains {"OperationLocks": {"LockReason" : "security"}}, all operations are prohibited.