Feature Overview
The scheduled snapshot feature is enabled for CBS snapshots so that developers can set backup task policies flexibly.
Using different scheduled snapshot policies for different businesses is advised. Recommended settings are given in the following table:
| Business Scenario | Snapshot Frequency | Retention Type |
|---|---|---|
| Core Business | Use scheduled snapshots, with the policy set to once a day. | 7-30 days |
| Non-core, Non-data Business | Use scheduled snapshots, with the policy set to once a week. | 1w |
| Archive Business | Snapshots are manually created considering actual business requirements, and no fixed frequency is to be set. | One month to a few months |
| Test Business | Snapshots are manually created considering actual business requirements, and no fixed frequency is to be set. | Delete upon use |
Policy Description
You can learn more about the contents and features of scheduled snapshot policies from the following table so that you can better use snapshots in your businesses.
| Policy Item | Description |
|---|---|
| Object | All cloud disks, including system disks and data disks. |
| Execution Policy | Automatic snapshot time point can be every hour to every day, which is valid for a long time after setting the execution policy. When an existing execution policy is changed, the policy will become valid upon successful change. |
| Regular Termination (Important) | Scheduled snapshots allow regular termination. The lifecycle of a snapshot is preset (1-30 days). Upon expiration, automatically generated snapshots will be automatically deleted so that backup cost is effectively reduced. If no regular termination policy is set, automatic snapshots will be retained for a long time. |
| Batch | Multiple cloud disks can be selected so that the same scheduled snapshot policy can be executed in batches for multiple cloud disks. No more than 80 cloud disks can be associated with the same snapshot policy in batches at a time. |
| Script pause | For a cloud disk that is out of use, no automatic snapshot policy will be executed. Out-of-use cloud disk means that the CVM associated with the cloud disk is shutdown or the data disk is not mounted. |
| Naming rules | Automatic snapshot name is snap_yyyyMMdd_HH. In which, yyyyMMdd is date and HH is hour. You can also manually change snapshot name. For example, snap_20180418_11 is an automatic snapshot created at 11:00 on April 18th, 2018. |
| Life Cycle (Important) | A snapshot has two types of lifecycle: - The lifecycle of a manually created snapshot is Long-term storage by default, and the snapshot can be preserved for a long time so long as the account balance is sufficient. - Scheduled snapshot: The time point of Regular Terminate can be set by following creation rules, and the snapshot can also be set as long-term retention. |
| Snapshot conflict | There is no conflict between automatic snapshots and custom snapshots in terms of use, but there may be time conflicts during creation. - When an automatic snapshot is executed on a disk, the user has to wait until the automatic snapshot is completed before a custom snapshot can be created (and vice versa). - If the disk has a large data size and the duration of a snapshot exceeds the interval between two automatic snapshot time points, no automatic snapshot will be created at the next time point. For example, if the user sets 9:00, 10:00, and 11:00 as automatic snapshot time points and the automatic snapshot use time at 9:00 is 70 minutes (it will be completed at 10:10), the automatic snapshot will not be executed at 10:00, and the next snapshot time point is 11:00. |
| Snapshot quota (available in later versions) | Every disk has a certain snapshot quota. If the number of snapshots in a disk is at the upper limit, the automatic snapshot task will be suspended and blocked. Snapshot quota is to avoid forgetting an automatic snapshot policy by the developer, otherwise, there will be an endless increase in storage cost. |
| ASP | Indicates the scheduled snapshot policy, i.e., Auto Snapshot Policy. |
| ASP quota (available in later versions) | No more than 30 ASP policies can be set for a region under a single account. A single ASP can be associated with up to 200 hard disks. |
| Preservation cycle | - For automatic snapshots, the console will display a countdown to recovery. Changing the automatic snapshot retention period to permanent retention is allowed. - For a manually created snapshot, the display will be retained permanently. |
| ASP pause function | ASP Auto Snapshot policy provides Manual Trigger Pause function. After pausing, no new snapshot will be automatically created. While the lifecycle of automatic snapshots generated will not be affected by the pause function, and the snapshot will be regularly terminated or stored for a long time depending on the set rules. |
| Operation Logs | The process of creation of all automatic snapshots will be displayed, which is the same as manually added ones. |
Operation Guide
Creating a Scheduled Snapshot Policy
Note:
No more than 30 scheduled snapshot policies can be created in the same region under a single account.
- Log in to the console and go to the Scheduled Snapshot Policy page.
- Select the Region.
- Click Create.
- On the Create Snapshot Policy page, set the following parameters and click OK.
The parameters are described as follows:
| Parameter | Parameter Description |
|---|---|
| Name | This parameter is required. Name of a scheduled snapshot policy, with no more than 60 characters. |
| Region | This parameter is required. This parameter cannot be changed on the current page. |
| Backup Cycle | This parameter is required. Set the cycle for executing regular snapshots. Backups can be scheduled by day, week, or month. |
| Backup Time | This parameter is required. The time point for executing a scheduled snapshot can be an hour in 00:00-23:00 (considering actual backend operation, the set time for timing snapshot may differ from the actual time when a snapshot is created through the console. For data in the snapshot, the time when the snapshot is created through the console will apply). |
| Retention Type | This parameter is required. - Supports retention by quantity. Automatically deletes when a fixed number is exceeded, up to 65,536 can be retained. - Supports retention by time. Automatically deletes after a fixed number of days, default retention is 1 month. - Permanently Save. |
Associating Cloud Disks
Note:
The same scheduled snapshot policy can be associated with no more than 200 cloud disks.
- Log in to the console and go to the Scheduled Snapshot Policy page.
- Select the Region.
- Click Associate Cloud Disk in the target policy row.
- On the Associate Cloud Disks page, check the cloud disk to be associated.
- Click OK.
Enabling/Disabling a Scheduled Snapshot Policy
- Log in to the Scheduled Snapshot Policy page.
- Select the Region.
- Find the target policy row, and click the switch button under Scheduled Snapshots to enable or disable a scheduled snapshot policy.
Changing a Scheduled Snapshot Policy
- Log in to the Scheduled Snapshot Policy page.
- Select the Region.
- Click Modify Policy in target policy row.
- On the Change Snapshot Policy page, change the related parameters and click OK.
Deleting a Scheduled Snapshot Policy
- Log in to the Scheduled Snapshot Policy page.
- Select the Region.
- You can delete a scheduled snapshot policy as stated below:
- Individual deletion: Click Delete in the target policy row.
- Batch deletion: Select the scheduled snapshot policies to be deleted, and click Delete at the top of the list.
Converting Automatic Snapshots to Permanently Retained Snapshots
Note:
If Snapshot Retention Period in an automatic snapshot policy has been set to Permanently Retention, the following operations are not required for snapshots automatically generated under the policy.
- Log in to the Snapshot List page.
- Select the Region.
- Click the ID of the target automatic snapshot.
- On the details page, click Edit and set the retention type to Permanently Save.
- Return to the snapshot list to see that the Snapshot Retention Period for that snapshot has been changed to Permanently Retention.