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 on RDS High-availability Edition. The database instance uses standard SSDs or enhanced SSDs for storage.
  • The balance in your Alibaba Cloud account is sufficient to pay for the resources that need to be consumed to expand the storage.
  • A DAS-linked role is created. For more information, see AliyunServiceRoleForDAS role.
    Note If the DAS-linked role 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. On the page that appears, click the ID of the database instance that you want to manage. 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 Autonomous Function Management > Autonomous Function Settings tab, enable the autonomy service.
  7. In the Optimization and Throttling section, select Automatic Space Expansion and specify the parameters described in the following table.
    Parameter Description
    The maximum number of available buckets When the remaining storage of the database instance is less than or equal to the value of the The maximum number of available buckets parameter, the system automatically expands the storage based on the larger value of the following items:
    • Storage space of 5 GB.
    • Fifteen percent of the current storage space of the instance.
    Maximum Storage of Automatic Expansion The maximum storage that can be increased by each operation for automatic storage expansion. Valid values: 150 to 32000. Unit: GB.
    Note The interval between two storage expansion operations is at least 10 minutes.
  8. In the message that is displayed, click OK.

Best practices

Handle storage insufficiency