Creating an Automatic Snapshot Policy

Scenarios

Protecting EVS disk data is critical during routine data management. However, snapshot creation may occasionally fail at scheduled times due to human error, resulting in service interruptions. Automatic snapshot policies allow you to define preset times at which standard snapshots are created automatically. This eliminates the risk of data loss if snapshots are not created manually. By using automatic snapshot policies, you can enhance data security and improve fault tolerance in service operations. This section describes how to create an automatic snapshot policy.

Constraints

• An EVS disk can retain up to 1,000 automatic snapshots. When this limit is reached, the system automatically deletes the oldest automatic snapshot.
• An account can retain up to 100 automatic snapshot policies in a region.
• If automatic snapshots are retained by time and the total retained snapshots reach 1,000, the system will still delete the oldest snapshot even if it is within the retention period.
• Retention rules apply only to snapshots created based on automatic snapshot policies. Manually created snapshots are not deleted automatically. If needed, you need to manually delete them from the snapshot list.
• An automatic snapshot policy supports up to 20 tags.
• Tag keys of the same automatic snapshot policy must be unique.

Procedure

1. Sign in to the EVS console.
2. In the navigation pane on the left, choose Elastic Volume Service > Snapshots.

   The Snapshots page is displayed.

3. On the Automatic Snapshot Policies tab, click Create Automatic Snapshot Policy.

   Configure the parameters of the snapshot policy.

   

   If this is your first time using this function, the system will prompt you to create an agency to authorize EVS to use the function.

   Table 1 Parameters required for creating an automatic snapshot policy

   Parameter	Description	Example Value
   Region	You can only apply an automatic snapshot policy to disks in the same region.	-
   Policy Name	A name must contain 1 to 64 characters including letters, digits, periods (.), underscores (_), and hyphens (-).	test_policy
   Frequency	Specify the interval between automatic snapshot policy executions. Weekly: Select one or multiple days from Monday to Sunday. Day based: Enter an integer ranging from 1 to 30.	Mon
   Execution Time	Set the times when automatic snapshots are created. The automatic snapshot creation starts within one hour after the specified execution time. You can select one or multiple hours from 00:00 to 23:00. NOTE: If there is a large amount of data, you are advised to take snapshots less frequent to prevent the system from skipping any execution time. For example, the snapshots of a disk are scheduled at 00:00, 01:00, and 02:00. A snapshot task starts at 00:00. Because there is a large amount of incremental data or a heap of snapshot tasks are executed at the same time, this snapshot task takes 90 minutes and completes at 01:30. EVS skips the snapshot task at 01:00 and takes the next snapshot at 02:00. In this case, only two snapshots are created in total, one at 00:00, and the other at 02:00. The execution times refer to the local times of the clients, not the times in the time zone of the region.	00:00, 08:00
   Retention Type	Rule that specifies how automatic snapshots will be retained By time: You can customize a retention duration. The system automatically deletes expired snapshots. The value ranges from 1 to 65536 days. Continuous retention: When the number of retained snapshots reaches the maximum allowed, the oldest snapshot is automatically deleted. NOTE: There are delays before the system deletes expired automatic snapshots.	Continuous retention
   Tag	Optional You can add tags to an automatic snapshot policy when creating the policy. Then, snapshots created by this policy will automatically inherit the tags of the policy. A tag consists of a tag key and a tag value. A tag key cannot start or end with a space, or start with _sys_. It can contain up to 128 characters including letters, digits, spaces, and the following special characters: _.:=+-@ A tag value can contain up to 255 characters including letters, digits, spaces, and the following special characters: _.:/=+-@	Tag key: test Tag value: 01
   Enterprise Project	An enterprise project facilitates project-level management and grouping of cloud resources and users. The default project is default. This parameter only shows up when you use an enterprise account to create an automatic snapshot policy.	default

4. Click Create Now.
5. (Optional) After the policy is created, the system displays a page where you can apply the policy to disks. You can select one or multiple disks. The system then automatically creates snapshots for the selected disks.
6. On the Automatic Snapshot Policies tab, check the created policy and perform operations such as applying the policy to disks and adding tags.

Helpful Links

• To check more snapshot FAQs, see Snapshot.
• Applying and Removing an Automatic Snapshot Policy
• Modifying an Automatic Snapshot Policy