Set an automatic snapshot policy for an instance
After you bind instance tags to an automatic snapshot policy, all disks attached to the matched instances are automatically included in backups, and you do not need to manually maintain the binding when disks are added or removed. When all disks attached to an instance belong to the ESSD family, a snapshot-consistent group is created first to ensure crash consistency and time-order consistency across multiple disks, which enables automated backup at scale.
Currently, setting automatic snapshot policies for instances is supported for only some customers. If you need this feature, submit a ticket to request access.
Features
Automatic binding with no maintenance: Disks are dynamically bound and unbound by instance tag. Each time an automatic snapshot is created, the policy retrieves the current instances and their attached disks by tag and creates snapshots for them. You do not need to manually adjust the policy binding when disks are added or removed.
Consistent backup data: By default, snapshots are created at the instance level for all attached disks. When a snapshot is created, the policy retrieves the current instances and their attached disks by tag. If all disks attached to an instance belong to the ESSD family, a snapshot-consistent group is created first. This suits large-scale, maintenance-free batch backup scenarios.
Scope
You have created an automatic snapshot policy whose association type is instance tags.
Make sure that the disks to be backed up are attached to an ECS instance, and the instance is in the Running or Stopped state.
Set an automatic snapshot policy for an instance
Step 1: Bind instance tags to the automatic snapshot policy
This applies only to automatic snapshot policies whose Associated Resources type is Instance Tags. For the Associate Disk type, see Set automatic snapshot policies for a disk.
Go to ECS console - Automatic Snapshot Policies. In the top navigation bar, select the resource group and the region of the target resources.
Click Actions in the Modify Policy.
In Associated Resources add the tags of the instances that you want to associate, and then click OK.
ImportantMultiple tags use an AND relationship: an instance must match all tags to be selected. Only custom tags are supported; system tags are not. A policy can be associated with a minimum of 1 tag and a maximum of 5 tags.
After a disk is detached from an instance, an instance is unbound from a tag, or a tag is removed from the policy, snapshots are no longer created for the affected disks starting from the next automatic snapshot creation time.
Step 2: Bind tags to instances
Bind tags to an existing instance
Go to ECS console - Instances. In the top navigation bar, select the resource group and the region of the target resources.
Click the target instance Tag in the
.and set tags.
If the instance has no tags, click Edit and enter the tag key and value that the automatic snapshot policy is bound to.
If the instance already has tags, click Edit and add the tag key and value that the automatic snapshot policy is bound to.
Bind tags to a new instance
On the instance purchase page, in the Management Settings section, click Add Tags.
Enter the tag key and value that the automatic snapshot policy is bound to.
For the other creation parameters, see Create an instance with Custom Launch.
After the policy runs, it generates automatic snapshots based on the disk type, or generates a snapshot-consistent group at the instance level:
All disks attached to the instance belong to the ESSD family (ESSD, ESSD AutoPL, and ESSD Entry): a snapshot-consistent group is created at the instance level.
In any of the following cases, a snapshot-consistent group cannot be created automatically, and a separate automatic snapshot is created for each disk attached to the instance:
The instance contains previous-generation disks (standard SSDs, ultra disks, or basic disks).
The instance contains ESSD zone-redundant disks.
ESSD zone-redundant disks can be included in a snapshot group only with disks of the same type. If such a disk exists, a separate automatic snapshot is created for it.
Modify an automatic snapshot policy
Modify the associated instance tags
Go to ECS console - Automatic Snapshot Policies. In the top navigation bar, select the resource group and the region of the target resources.
Click Actions in the Modify Policy.
In Associated Resources section, modify the associated instance tags.
A policy can be associated with a minimum of 1 tag and a maximum of 5 tags.
Delete an associated instance tag: click the option after the instance tag that you want to modify, and then click
click OK.Add an associated instance tag: Enter the tag key and value that you want to bind, and then click OK.
ImportantMultiple tags use an AND relationship, so only instances that match all tags are associated. After you make changes, click View Associated Instances to confirm that the association scope is as expected before you proceed. This helps prevent accidental deletion and protects your data.
Unbind a disk attached to an instance
You cannot change the association type. To unbind a single disk, you must detach it from the instance. Only then is the automatic snapshot policy canceled for the disk.
Billing
Creating a snapshot policy is free of charge, but running the policy incurs fees based on the task type. You can reduce snapshot storage costs by deleting automatic snapshots when the disk is released, archiving snapshots, and periodically deleting snapshots that you no longer need. For more information, see Reduce snapshot storage costs.
Automatic snapshot creation tasks: All snapshots created by the policy are billed by snapshot capacity at the standard snapshot storage fee.
Cross-region replication tasks: If the policy has cross-region replication enabled, in addition to the standard snapshot fee in the source region, you also incur a snapshot replication traffic fee and the standard snapshot storage fee in the destination region.
Quotas and limits
Tag binding limits: An instance must match all tags to be selected. Only custom tags are supported; system tags are not. A policy can be associated with a minimum of 1 tag and a maximum of 5 tags.
Recommended number of associated instances: Avoid associating too many instances with the policy through instance tags. If the tags match a large number of instances, automatic snapshot creation may slow down, and in extreme cases, automatic snapshots for some instances may be skipped or missed. Plan the number of associated instances based on your business scale.
Maximum number of tasks: Each disk has an upper limit on the number of concurrent snapshot creation tasks (including both automatic and manual tasks). If a disk attached to the instance exceeds the maximum number of tasks when the policy is triggered, the task for that disk is skipped and reevaluated at the next scheduled time. The task limits for different disk types are as follows:
Disk type
Maximum number of tasks
ESSD family disks (ESSD, ESSD AutoPL, ESSD Entry, and ESSD zone-redundant)
10
Previous-generation disks (standard SSDs, ultra disks, basic disks)
1
When cross-region replication is enabled for the policy, make sure that the disks attached to the instance do not already have a cross-region replication task with the same source and destination regions. If such a task exists, the new task is skipped and reevaluated at the next scheduled time.
For the maximum number of automatic snapshots per disk, see Snapshot limits.When automatic snapshots reach the maximum limit, the system deletes the oldest unlocked automatic snapshot generated by the policy, even if its retention period has not expired. Plan carefully based on your business needs to avoid unintentionally deleting important snapshots.
By default, automatic snapshots are crash-consistent and contain only the data that has been written to the disk, not the data in memory. If your workloads have strict data consistency requirements, we recommend that you periodically create application-consistent snapshot.
More operations
Delete automatic snapshots when the disk is released
After you enable the Delete Automatic Snapshots While Releasing Disk attribute, releasing the disk (by manually releasing the disk, releasing the disk together with the instance, or replacing the operating system) also deletes automatic snapshots that have not yet expired.
Go to ECS console - Block Storage - Cloud Disks. In the top-left corner, select the region and resource group for the target resource.
In the Actions column of the target disk, click
In Modify Disk Attributes In the dialog box, select the Delete Automatic Snapshots While Releasing Disk option.
You can clear the option later to disable it. Delete Automatic Snapshots While Releasing Disk.
Click Confirm.
View the created automatic snapshots
In ECS console - Snapshots page to view the automatic snapshots that are created.
Automatic snapshots are named in the format auto2.0_yyyyMMdd_SnapshotPolicyId, and the Snapshot Type is Automatic Snapshot.
auto2.0: indicates an automatic snapshot.
For the difference between manual and automatic snapshots, see Differences between manual and automatic snapshots
yyyyMMdd: the date on which the snapshot is created, where y is the year, M is the month, and d is the day.
SnapshotPolicyId: the ID of the automatic snapshot policy that the snapshot belongs to.
For example, auto2.0_20260802_sp-2zeff8vy17u91rn5**** indicates a snapshot-consistent group created on August 2, 2026, with the automatic snapshot policy ID sp-2zeff8vy17u91rn5****.
For an automatic snapshot that belongs to a snapshot-consistent group, you can view the tag and obtain the snapshot-consistent group ID from theacs:ecs:snapshotGroupId corresponding tag value.