Before performing critical operations such as rolling back disks, modifying system files, or replacing operating systems, it is recommended to create snapshots for system or data disks to back up data. In the event of unexpected issues or data loss, these snapshots can be used to restore data and ensure business continuity.
Note
This topic describes how to manually create a snapshot for a single cloud disk.
Prerequisites
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Snapshots are activated. For more information, see Activate snapshots.
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Ensure the cloud disk is in In Use or To Be Attached status.
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If the cloud disk is in In Use status, the instance must be in Running or Stopped status.
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If the cloud disk is in To Be Attached status, it must have been previously attached to an ECS instance. Cloud disks that have never been attached do not support snapshot creation.
Note
Cloud disks that have never been attached to ECS instances do not require snapshots, as the data remains unchanged after creation.
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Ensure the cloud disk supports snapshot creation.
Note
You cannot create snapshots for local disks or elastic ephemeral disks.
Considerations
Please consider the following before creating a snapshot:
Consideration | Description |
Impact on performance | At the initial moment of snapshot creation (usually a few seconds), the I/O performance of the cloud disk is affected, generally by no more than 10%. Once the snapshot upload progresses, the read and write performance of the cloud disk returns to normal and is no longer affected. Therefore, it is recommended to create snapshots during off-peak hours or when I/O latency is not a concern to minimize the impact on business operations. |
Creation duration | The time required to create a snapshot depends on multiple factors, such as the data volume of the snapshot, the number of snapshots being created by other users, and the snapshot size. After a snapshot is created, it is automatically stored in Object Storage Service (OSS). A longer period of time is required to upload a larger snapshot to OSS. Note The first snapshot of a disk is a full snapshot and takes an extended period of time to be created. Subsequent snapshots are incremental snapshots and do not require the same amount of time to be created as the first snapshot. The amount of time required to create an incremental snapshot varies based on the amount of data changed since the previous snapshot. Early morning is usually the peak period for automatic snapshot creation. The number and size of snapshots being uploaded increase, and the bandwidth allocated to each snapshot may decrease, resulting in longer creation times. If business operations allow, it is recommended to avoid creating snapshots during this period to achieve better upload speeds. Note The initial upload time required for snapshot creation may be relatively long. However, as time progresses and the number of snapshots being uploaded decreases, the remaining snapshots can enjoy more bandwidth, resulting in faster upload speeds and shorter estimated remaining upload times.
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Billing description | After a snapshot is created, the system calculates the snapshot storage fees based on the snapshot size in each region. For more information, see Snapshot billing. |
Other considerations | Do not modify the ECS instance status (such as stopping or restarting) during snapshot creation. Otherwise, the snapshot creation will fail. While snapshots are being created, the incremental data generated by disk operations is not included in the snapshots. You cannot resize a disk for which a snapshot is being created. If you need to resize the disk, wait until the snapshot creation is complete before performing the resize operation. When a disk is used to create a logical volume or RAID array, it is recommended to use snapshot consistency groups and enable application-consistent snapshots to ensure data write sequence and crash consistency. For more information, see Snapshot consistency groups. The following limits are imposed on manual and automatic snapshots: If a snapshot is being manually or automatically created for a cloud disk when the point in time specified in the associated automatic snapshot policy is reached, the automatic snapshot cannot be created based on the policy at the point in time. An automatic snapshot is created for the disk at the next point in time specified in the automatic snapshot policy. If an automatic snapshot is being created for a cloud disk, you cannot create a manual snapshot for the disk. Wait until the automatic snapshot is created.
After a snapshot is created, the snapshot is automatically stored in an OSS bucket. You cannot select an OSS bucket to store the snapshot or view the snapshot data. For more information, see Snapshot storage locations.
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Procedure
This section explains how to create a snapshot for a disk on the Snapshots page in the ECS console. Snapshots can also be created on the Block Storage (Disks) page.
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Navigate to the Snapshots page.
Log on to the ECS console.
In the left-side navigation pane, choose .
In the top navigation bar, select the region and resource group to which the resource belongs. 
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On the Disk Snapshots tab, click Create Disk Snapshot.
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In the Create Snapshot dialog box, set the snapshot parameters, then click Confirm.
Parameter | Description |
Resource Type | The default selection is Disk, which allows you to create a snapshot for a single disk. Note You can also select Instance to select one or more disks from the instance, create a snapshot consistency group, and create snapshots for multiple disks within the group to ensure data consistency across multiple disks. For more information, see Create a snapshot consistency group. |
Select Disk | Select the disk for which you want to create a snapshot. You can select a system disk or a data disk. |
Snapshot Name | Specify a name for the snapshot. |
Retention Period | Set the retention period for the snapshot. You can choose to retain it permanently or specify a custom number of days. Permanently: After the maximum number of snapshots is reached, new snapshots cannot be created. Custom retention period: The snapshot will be automatically deleted by the system after the retention period expires.
Note For the upper limit of manually created snapshots, see Snapshot overview. If you choose a custom retention period, when the retention period is 3 days away from expiration, the Retention Period column in the snapshot list will highlight Automatically Released In Xx Days. You can extend the retention period before the snapshot expires as needed. For more information, see Extend snapshot retention period. Regardless of whether the retention period is permanent or custom, if you no longer need the snapshot, it is recommended to delete it promptly to avoid incurring ongoing snapshot fees. For more information, see Delete a snapshot.
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Advanced Configuration | Instant Availability | ESSD series disks (ESSD, ESSD AutoPL, ESSD Entry, and ESSD zone-redundant storage) have the instant availability feature enabled by default. Other types of disks do not have this feature enabled by default. Note The instant availability feature allows snapshots to be available within seconds after creation, without waiting for the snapshot to be uploaded to OSS. You can use the snapshot immediately for operations such as rolling back disks, creating new disks, or sharing snapshots. For more information, see Snapshot instant availability. |
Tags | Set the tag key-value pairs for the snapshot. You can use the tag feature to manage resources in a unified manner. |
Resource Group | Set the resource group to which the snapshot belongs. You can use resource groups to manage snapshots at different levels. |
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(Optional) Monitor the creation progress of the snapshot on the Disk Snapshots tab.
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In the Progress column, check the upload progress to OSS. Hover over Upload To OSS: Xx% to see the estimated remaining time.
Note
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The estimated time to upload a snapshot to OSS may vary based on several factors. For details, refer to the Creation duration section in Considerations.
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To cancel a snapshot creation task in progress, use the DeleteSnapshot API operation.
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When the Progress column shows Upload To OSS: 100%, the snapshot upload to OSS is complete, and the disk data backup is successful.
Elastic Compute Service (ECS)
Container Compute Service (ACS)
