ApsaraDB RDS:Configure automatic storage expansion

Prerequisites

• Your RDS instance uses cloud disks and runs RDS High-availability Edition or RDS Cluster Edition.

  Note

  • You cannot separately configure automatic storage expansion for read-only RDS instances.

  • For more information about how to configure automatic storage expansion for RDS instances that run different database engines, see the following topics:

    • ApsaraDB RDS for MySQL instances: Use the automatic storage expansion feature for an ApsaraDB RDS for MySQL instance

    • ApsaraDB RDS for PostgreSQL instances: Use the automatic storage expansion feature for an ApsaraDB RDS for PostgreSQL instance

• The balance of your Alibaba Cloud account is sufficient to pay for the resources that are required to expand storage space.

• A service-linked role is created for DAS. For more information, see AliyunServiceRoleForDAS role.

  Note

  If no service-linked role is created for DAS, the system automatically creates the role before the system expands storage space.

Usage notes

• If your database instances include read-only instances, DAS automatically checks the storage space of each read-only instance when automatic space expansion is triggered for the primary instance. If the storage space of a read-only instance is smaller than the storage space to which that of the primary instance is expanded, DAS first expands the storage space of the read-only instance. When the storage space of all read-only instances meets the requirement, DAS automatically expands the storage space of the primary instance.

• The automatic space expansion feature cannot be used for some ApsaraDB RDS for SQL Server instances due to the restrictions of Windows drivers. In this case, we recommend that you update the minor engine version of these database instances. For more information, see Update the minor engine version of an ApsaraDB RDS for SQL Server instance.

• After the storage space of your database instance is expanded, the storage space cannot be automatically reduced. However, you can manually reduce the storage space by changing the instance specifications. For more information, see Change instance specifications.

  Note

  You cannot manually reduce the storage space of ApsaraDB RDS for SQL Server instances.

Billing

The billing rules for automatic space expansion are the same as those for manual space expansion of ApsaraDB RDS instances. For more information, see Specification changes.

Procedure

1. Log on to the DAS console.

2. In the left-side navigation pane, click Instance Monitoring.

3. On the page that appears, 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 of the page that appears, click Autonomy Center.

5. In the upper-right corner of the Autonomy Center tab, click Autonomy Service Settings.

6. On the Autonomous Function Settings tab of the Autonomous Function Management panel, enable the automatic storage expansion feature.

7. On the Optimization and Throttling tab, select Automatic Space Expansion and configure the following parameters.

   Parameter	Description
   Available Storage Space ≤	The threshold for triggering automatic storage expansion. When the remaining storage of the instance is less than or equal to the value of this parameter, the system automatically expands the storage capacity based on the larger value between the following items: 5 GB 15% of the storage capacity of the instance For example, if the total storage capacity is 100 GB, the storage capacity is expanded by 15 GB when the threshold is reached. After the expansion, the total storage capacity is 115 GB.
   Maximum Storage of Automatic Expansion	The maximum storage capacity of the RDS instance after the storage capacity expansion. The value of this parameter must be greater than or equal to the storage capacity of the RDS instance.

   Note

   The minimum interval between two consecutive storage capacity expansion events is 10 minutes.

8. Click OK.

View the results of automatic space expansion

1. Log on to the DAS console.

2. In the left-side navigation pane, click Instance Monitoring.

3. On the page that appears, 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. On the Autonomy Center page, select a time range and find the Auto-Scaling Events that occurred within the selected time range.

6. Click Details to view the details of automatic space expansion.