What are ECS snapshots

Last Updated: May 22, 2018

A snapshot is a copy of data on an elastic block storage device at a given time point. For more information about how snapshots are created, see Incremental snapshot mechanism.

Note: Creation of a snapshot may reduce the I/O performance of a block storage device, generally by less than 10%, resulting in sharp decrease in I/O speed. We recommend that you create snapshots during off-peak business hours.


Currently, Alibaba Cloud provides Snapshot 2.0 service. Compared with the former version, Snapshot 2.0 has better performance in capacity limit, scalability, cost, and usability. For more information, see ECS Snapshot 2.0 vs. traditional storage products.

Note: Unless and otherwise specified, either “snapshot” or “snapshot service” in all ECS articles is assumed as Snaphsot 2.0 service.


The snapshot service meets your requirements, such as:

For more information, see Scenarios.


Snapshots are classified into two categories:

  • Manual snapshots, which are created manually. You can create snapshots for an elastic block storage device at any time to back up data. For more information, see Create a snapshot.

  • Auto snapshots, which are created automatically according to the automatic snapshot policy applied to an elastic block storage device. You can create an automatic snapshot policy and apply it to the storage device. Then snapshots will be created automatically at the given time points.


Currently, the snapshot service is free of charge.

View the size of snapshots

A snapshot chain of an elastic block storage device is created once the first snapshot is created. You can view the total size of the snapshots of an elastic block storage device by using the Snapshot Chain feature in the ECS console.


All the snapshots of encrypted cloud disks or shared block storage are encrypted. These snapshots are called encrypted snapshots. Encrypted snapshots cannot be converted to unencrypted snapshots, and vice versa. For more information, see ECS disk encryption.

Delete snapshots

If your business no longer requires a snapshot of an elastic block storage device, you can delete the snapshot. If you have applied an automatic snapshot policy to the storage device, you can delete the automatic snapshot policy.

Thank you! We've received your feedback.