You can use Database Autonomy Service (DAS) to monitor the storage of your database instance. When the storage is insufficient, DAS automatically expands the storage to ensure that your business is stable.


  • The database instance is an ApsaraDB RDS for MySQL instance of the High-availability Edition or an ApsaraDB RDS for PostgreSQL instance of the High-availability Edition. The database instance uses standard SSDs or ESSDs for storage.
  • The Enable Autonomy Service switch is turned on for the database instance. For more information, see Autonomy center.
  • The balance in your Alibaba Cloud account is sufficient to pay for the resources that need to be consumed to expand the storage.
  • The service linked role for DAS is created. For more information, see AliyunServiceRoleForDAS role.
    Note If the service linked role for DAS is not created, DAS automatically creates the role before the automatic storage expansion feature expands the storage of your database instance.


The billing rules for automatic storage expansion are the same as the billing rules for manual storage expansion of an ApsaraDB RDS instance. For more information, see Specification change fees.


  1. Log on to the DAS console.
  2. In the left-side navigation pane, click Instance Monitoring.
  3. Find the database instance that you want to manage and click the instance ID. The instance details page appears.
  4. In the left-side navigation pane, click Autonomy Center.
  5. In the upper-right corner of the Autonomy Center tab, click Autonomy Service Settings.
  6. In the Settings dialog box, turn on the Enable Autonomy Service switch on the Autonomy Service Settings tab.
  7. Turn on the Automatic Resource Elasticity switch and configure the following parameters.
    Parameter Description
    Available Storage Space When the remaining storage of the database instance is less than or equal to the value specified by Available Storage Space, the system automatically expands the storage based on the largest value of the following items:
    • 5 GB
    • 15 percent of the total storage of the database instance
    • To-be-used storage that is predicted based on the values of the disk_usage metric in the previous 7 hours
    Maximum Storage of Automatic Expansion The maximum storage that can be increased by each operation for automatic storage expansion. Valid values: 100 to 32000.
    Note The minimum interval for storage expansion is 10 minutes.
  8. Click OK.

Best practices

Handle storage insufficiency