A snapshot records the disk data state at a specific point in time point that can be used for easier data backup and image customization.

Scenarios

You can create a snapshot for data backup scenarios. For example, you can create a snapshot if you need to modify critical system files, migrate instances from a classic network to a VPC, back up data routinely, mitigate network attacks, change the operating system, or provide data support for a production environment.

Additionally, you can use a snapshot to create customized images for quick application environment deployment in a large number of instances.

Precautions

  • Creating a snapshot may impact disk performance and I/O performance. We recommend that you create a snapshot during off-peak business hours.
  • A snapshot only records data at a specific point in time. Therefore, incremental data generated by disk operations during snapshot creation is not synchronized to a created snapshot.
  • To guarantee successful snapshot creation, we recommend you do not modify the ECS instance status (that is, stop or restart the instance) during snapshot creation.
  • If you want to create a snapshot based on an instance, the instance must be in Running or Stopped status.
  • If you want to create a snapshot based on a disk, the disk must be in Running status.
  • Manually created snapshots must be manually deleted. Therefore, you need to delete unnecessary snapshot to prevent continuous deduction caused by increasing snapshot capacity.
  • If you create an extended volume by using a multi-partition single disk, the snapshots you created can be used for rolling back a cloud disk.
  • After you create a dynamic extended volume by using multiple disks and no I/O operation is performed on data in the extended volume, the snapshot you created can be used for disk rollback. If I/O operations are continuously performed in the extended volume, data consistency of the rolled-back disk is uncertain.

Procedure

To create a snapshot on the ECS console, follow these steps:

  1. Log on to the ECS console.
  2. Select the target region.
  3. In the left-side navigation pane, click Instances.
  4. Locate the instance for which you want to create a snapshot and click Manage in the Actions column.

  5. In the left-side navigation pane, click Disks, locate the target disk, and then click Create Snapshot. You can select only one disk at a time. Type can be either system disk or data disk.

  6. Enter a name for the snapshot and click OK.

  7. In the left-side navigation pane, click Instance Snapshots. Here, you can see the creation progress, estimated remaining time, and status of the snapshot.

Alternatively, you can use the ECS API CreateSnapshot to create a snapshot.

Time required

The time required for creating a snapshot depends on the disk capacity.

According to the incremental snapshot mechanism, the first disk snapshot records full disk data, which takes an extended amount of time. However, subsequent snapshots are generally created in a shorter time. However, the exact time required depends on the amount of data generated since the first snapshot creation. The larger the data amount is, the longer time the snapshot creation will take.

What to do next

After you create a snapshot, you can: