Creating a Backup Policy

Log in to the CBR console.
Choose Policies in the navigation pane. In the upper right corner, click Create Policy. Figure 1 shows an example.
Figure 1 Creating a backup policy

Set the backup policy parameters.

**Table 1** Parameter description
Parameter	Description	Example Value
Type	Policy type.	Backup
Policy Name	Backup policy name. You can enter a custom name or use the default name policy_xxxx. A name contains a maximum of 64 characters. Only letters, digits, underscores (_), and hyphens (-) are allowed.	backup_policy
Status	Whether to enable the backup policy. By default, a backup policy is enabled. CBR backs up servers and EVS disks to a vault and deletes expired backups only after a backup policy is applied to the vault.	Enable
Backup Frequency	Frequency for executing a backup task. By default, a backup task is executed automatically every Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, and Sunday. Weekly Specify on which days of each week a backup task will be executed. You can select multiple days. Day-based Specify the interval (1 to 30 days) for executing a backup task. If you select Day-based, the first backup time is supposed to be on the day when the backup policy was created. If the specified backup time has passed when you create a backup policy, the initial backup will be performed in the next backup cycle. You are advised to execute backup tasks during off-peak hours or when there are no services running.	Every 1 day
Execution Time	Execution time of a backup task in a day. The default backup time is 22:00. You can select multiple times, either on or off the hour, for backup. If you select a time that is not on the hour, you can customize the time (0 to 59 minutes). For example, you can select a time that is not on the hour, such as 00:10 and 01:10. You are advised to execute backup tasks during off-peak hours or when there are no services running. The backup service experiences peak usage between 22:00 and 08:00, during which delays may occur. To ensure optimal performance, it is recommended that you evaluate your service types and stagger backups across discrete time periods. NOTICE: There may be a time difference between the scheduled backup time and the actual backup time. If you have a large amount of data to back up, you are advised to set a less frequent backup schedule. If a backup task takes longer than the backup interval, the system will skip the next backup execution time. For example, a disk is scheduled to be backed up at 00:00, 01:00, and 02:00. A backup task starts at 00:00. Because a large amount of incremental data needs to be backed up or a heap of backup tasks are executed at the same time, this backup task takes 90 minutes and completes at 01:30. The scheduled backup at 01:00 will be skipped. There will be only two backups generated, one at 00:00, and the other at 02:00. The execution times refer to the local times of clients, not the time zone or times of the region.	00:00, 02:00
Full Backup	Whether to perform periodic full backups. By default, full backup is disabled. Enable Enabling full backup improves your data reliability, but full backups will use more storage space. Configure a full backup frequency. The value ranges from 0 to 100. 0 means that a full backup will be performed in every backup task. Disable Incremental backups will be performed based on the backup policy. NOTICE: A full backup usually takes a long period of time. If a full backup of a resource is in progress, other policy or manual backups of this resource will not be performed. You are advised to back up data during off-peak hours. When backups are kept by quantity, full backups can be performed only when the full backup frequency configured is less than the number of retained backups. If full backup is not enabled, to ensure data security, a full backup is performed after 365 incremental backups by default.	7
Retention Rule	Rule that specifies how backups will be retained. By default, backups are retained for one month. Time period You can choose to retain replicas for one month, three months, six months, or one year, or for any desired number (2 to 99999) of days. Backup quantity You can set the maximum number of backups to retain for each cloud server. The value ranges from 2 to 99999. Advanced Options You can also set long-term retention rules with advanced options. Long-term retention rules and quantity-based retention rules will be both applied. Day-Based: The most recent backup of each day is retained. Range: 0–100 Weekly: The most recent backup of each week is retained. Range: 0–100 Monthly: The most recent backup of each month is retained. Range: 0–100 Yearly: The most recent backup of each year is retained. Range: 0–100 For example, if you select Day-Based, the system retains the most recent backup each day. If a disk is backed up for multiple times in a day, only the most recent backup of that day is retained. If you set the value for Day-Based to 5, the system retains the most recent backup from each of the last five days that have backups generated. If there are more than five backups, the earliest backup will be deleted automatically. If Day-Based, Weekly, Monthly, and Yearly are all configured, the union backups will be selected for retention. For example, if Day-Based is set to 5 and Weekly to 1, five backups will be retained. The long-term retention rule and the quantity-based retention rule will both apply. Permanent NOTE: The system automatically deletes the earliest and expired backups every other day to avoid exceeding the maximum number of backups to retain or retaining any backup longer than the maximum retention period. Retained backups may not be deleted immediately after the expiration time specified in the backup policy. There may be a delay. Generally, they are deleted in batches from 8:00 to 20:00 after the expiration time. For example, if a backup expired at 20:00 on November 23, 2024, it was deleted from 08:00 to 20:00 on November 24, 2024. In this way, backup data can be deleted during off-peak hours. A retention rule only applies to backups generated by automatically executing a backup policy. It does not take effect for those generated by manually executing a backup policy. You can manually delete them from the backup list. If a backup is used to create an image, the backup will not be deleted by a retention rule. Instead, it will be forcibly retained. After the image created from the backup is deleted, the retention rule will apply to the backup. That is, if the backup expires or is not within the most recent backups, it will be deleted automatically. A maximum of 10 backups can be retained for failed periodic backup tasks. They are retained for one month and can be deleted manually. A backup cannot be deleted before the subsequent backup task is complete.	Select Backup quantity and set to keep 3 backups. In addition, select Advanced Options and set to keep the most recent backup from each of the last two weeks. If today is the 30th of a month, the execution of this policy is shown in Figure 3. Dates with a time indicate the days that have backups generated. Dates with the time in gray indicate that the backups have been deleted. Dates with the time in green indicate that the backups are retained. If the weekly retention rule in advanced options is not configured, only the backups generated on the 25th, 26th, and 29th will be retained.

Figure 2 Retention rule with advanced options configured
Click to enlarge

Figure 3 Retention rule execution example

Frequent backups, more retained backups, or a longer retention can improve data protection, but those backups will also take up more space. Configure an appropriate backup policy based on the data importance and service volume.