Why Does the Retention Rule Not Take Effect After Being Modified?

A retention rule does not take effect immediately after being modified in the following scenarios:

• The retention rule remains to be by backup quantity, with only the configured quantity changed:

  The new retention rule takes effect when the backup policy is executed next time, and the new retention rule still takes effect for the backups generated by the original backup policy.

  For example: At 10:00 a.m. on Monday, a user sets the backup execution time of policy A to 02:00 a.m. every day, sets the rule to retaining three backups, and associates a disk. At 10:00 a.m. on Thursday, three backups are retained. Then the user modifies the retention rule to retaining one backup. However, this retention rule does not take effect immediately. Instead, it retains only the generated backup at 02:00 a.m. on Friday. At then, the three backups generated by the original policy have been deleted.

• The retention rule is changed from by quantity to by time:

  The new retention rule does not take effect on the backups generated by the original backup policy. The backups generated by the original backup policy will not be automatically deleted.

  For example: At 10:00 a.m. on Monday, a user sets the backup execution time of policy A to 02:00 a.m. every day, sets the rule to retaining three backups, and associates a disk. At 10:00 a.m. on Thursday, three backups are retained. Then the user modifies the retention rule to deleting the backup generated one month ago. At 02:00 a.m. on Friday, the backup generated by the new backup policy is retained and the three backups generated by the original policy still exist.

• The retention rule remains to be by time period, with only the configured time period changed:

  The new retention rule does not take effect on the backups generated by the original backup policy, but only on the new backups. The backups generated by the original backup policy still follow the original retention rule.

  For example: At 10:00 a.m. on August 5, a user sets the backup execution time of policy A to 02:00 a.m. every day, sets the retention rule to deleting the backup generated one month ago, and associates a disk. At 10:00 a.m. on August 8, three backups are retained. Then the user modifies the retention rule to deleting the backup generated three months ago. At 02:00 on September 6, the backup generated by the original backup policy on August 6 is deleted, and the backup generated on August 9 will be deleted two months later.

• The retention rule is changed from by time to by quantity.

  The new retention rule does not take effect on the backups generated by the original backup policy, but only on the new backups. The backups generated by the original backup policy still follow the original retention rule.

  For example: At 10:00 a.m. on August 5, a user sets the backup execution time of policy A to 02:00 a.m. every day, sets the retention rule to deleting the backup generated one month ago, and associates a disk. At 10:00 a.m. on August 8, three backups are retained. Then the user modifies the retention rule to retaining one backup. At 10:00 on August 10, the backup generated on August 9 has been deleted and the backup generated on August 10 is retained. However, the backups generated on August 6, 7, and 8 still exist. At 02:00 on September 6, the backup generated on August 6 is deleted.