Create an automatic snapshot policy to periodically create snapshots for cloud disks to back up data - Elastic Compute Service

An automatic snapshot policy periodically creates snapshots for specified cloud disks. This practice prevents data loss from human error and improves system reliability. The policy also supports cross-region replication for snapshots, which lets you quickly restore data in another region after a regional disaster or failure.

Prerequisites

The Elastic Compute Service (ECS) snapshot service must be activated. For more information, see Activate ECS Snapshot.

Procedure

Note

If you have no snapshot policies in the current region, the system creates a default policy (default_policy) the first time you assign a policy to a cloud disk. You can use the default policy or create a custom one.

Go to ECS console - Automatic Snapshot Policies.
In the top navigation bar, select the region and resource group of the resource that you want to manage.
On the Automatic Snapshot Policies tab, click Create Automatic Snapshot Policy.

On the Create Automatic Snapshot Policy page, configure the parameters and click OK.

Policy details

Configure the basic information for the policy, such as its name, execution schedule, and snapshot retention period.

Parameter	Description
Policy Name	Enter a name for the policy.
Execution Frequency	Select one or more days of the week (Monday to Sunday) on which to create automatic snapshots.
Execution Time	The time of day to create the automatic snapshots. The time is in UTC+8 and is specified by the hour. The system creates the automatic snapshot within one hour after the specified Execution Time. If you need to create multiple snapshots in a single day, you can select multiple hourly time slots from 00:00 to 23:00. Important Creating a snapshot can temporarily reduce I/O performance by up to 10%, causing brief slowdowns. Schedule snapshots during off-peak hours.
Retention Period	Specify how long to keep automatic snapshots. Custom Period: Snapshots are automatically deleted after the specified retention period expires. Until Deleted: When the automatic snapshot quota is reached, the system deletes the oldest snapshot to make room for a new one. Note If you select a custom retention period, the Retention Period column in the snapshot list highlights snapshots as Released After {days} Days when they have 3 days remaining before expiration. You can extend the retention period before a snapshot expires. For more information, see Extend the retention period of a snapshot. For information about the automatic snapshot quota, see Limits. After you create a snapshot policy, you can modify its retention period. For more information, see Modify an automatic snapshot policy. The new retention period applies only to new automatic snapshots created by the policy and does not affect existing snapshots. For example, if existing snapshots have a retention period of 20 days and you change the policy's retention period to 10 days, the existing snapshots are still retained for 20 days. If the Delete Automatic Snapshots While Releasing Disk attribute is enabled for a cloud disk, the snapshot is deleted along with the cloud disk when the disk is released. This occurs even if the snapshot's retention period has not expired. A disk is released when you manually release it, its instance is released, or you replace its system disk. Regardless of whether a snapshot has a custom or indefinite retention period, you can delete it at any time to avoid ongoing storage costs. For instructions, see Delete a snapshot.

Cross-region replication

Important

Replicating a snapshot creates a copy in the destination region and incurs cross-region data transfer fees. The snapshot copy in the destination region also incurs storage fees based on its size and retention period. For more information, see Snapshots.
For more information about snapshot replication, see Copy a snapshot.

Parameter	Description
Cross-region Snapshot Replication	When enabled, snapshots created by this policy are automatically replicated to the destination region for data backup and disaster recovery.
Destination Region	Select the region to which you want to replicate the snapshots.
Retention Period of Snapshot Copies	Specify the retention period for the snapshot copies in the destination region.
Copy and Encrypt	Disabled: If the source snapshot is encrypted, the system uses a service-managed key from Key Management Service (KMS) in the destination region to encrypt the replicated snapshot. If the source snapshot is unencrypted, the copy remains unencrypted. Enabled: Regardless of whether the source snapshot is encrypted, snapshots created by this policy are replicated and encrypted in the destination region using a key that you specify. For more information about ECS encryption, see Disk encryption.

Advanced Settings

Parameter

Description

Tag

Select or enter tags to apply to snapshots created by this policy. For information about tags, see Tags.

You can modify the tags of an automatic snapshot policy after it is created. For more information, see Edit the tags of an automatic snapshot policy.

Resource Group

Select an existing resource group to organize your snapshot policies. For more information, see Resource groups.

After creating the policy, apply it to your cloud disks to enable automatic backups.
For instructions, see Configure an automatic snapshot policy for a cloud disk.