Configure automatic storage expansion

Background information

For detailed background information, see DAS Auto Scaling elasticity capabilities.

Notes

• If a database instance has read-only instances and the primary instance triggers automatic space expansion, the system checks the storage size of each read-only instance. If any read-only instance has less storage than the target size of the primary instance, the system expands the read-only instance storage first. After all read-only instances are expanded, the primary instance storage is expanded.

• Due to Windows driver limitations, some instances cannot use this feature. We recommend that you upgrade the minor engine version.

• Automatic scale-in is not supported after automatic expansion.

Billing

The billing rule is the same as manually upgrading RDS instance storage capacity. For details, see Billing rules for upgrades and downgrades.

Procedure

1. Go to the Instances page. In the top navigation bar, select the region in which the RDS instance resides. Then, find the RDS instance and click the ID of the instance.

2. In the Instance Resources section, click Settings next to Automatic Storage Expansion.

3. Configure the following parameters and click OK.

   Category	Description
   Automatic Storage Expansion	Enables or disables automatic storage expansion.
   Available Storage ≤	Triggers automatic expansion when the percentage of remaining storage space reaches the specified value. Note The expanded storage size is the larger of the following two values: 5 GB. If the total instance storage is less than 50 GB and free space is below 10%, the scaling step size becomes 10 GB. 15% of the current instance storage capacity (rounded to the nearest multiple of 5).
   Maximum Storage Capacity:	The upper limit for automatic expansion. It must be greater than or equal to the current total storage capacity of the instance. Enterprise SSD limit: 32000 GB Premium ESSD limit: 32000 GB Maximum standard SSD capacity: 6000 GB

View expansion history

1. Go to the Instances page. In the top navigation bar, select the region in which the RDS instance resides. Then, find the RDS instance and click the ID of the instance.

2. In the Instance Resources section, click Storage Expansion Records next to Automatic Storage Expansion to open the Database Autonomy Service console.

3. On the Autonomy Center page, set Type to Auto scaling event to view past storage expansion events.

   Each record in the event list shows the event level, occurrence time, and duration. Click Details to view specific information about an expansion event.

4. Click Details for the target auto scaling event to view expansion specifics.

   On the Recommendations tab of the scaling details page, the Issues and Recommendations section shows instance disk space usage and scaling recommendations. The Storage Recommendations section displays the original and recommended storage capacities (for example, original storage 100 GB, recommended storage 115 GB). The Execution Status section shows the status and results of each task, such as calls to RDS OpenAPI and specification changes executed by the control plane.

   Issues and RecommendationsStorage RecommendationsExecution Status

References

• Besides the automatic storage expansion feature described in this topic, you can also manually increase instance storage capacity. For instructions, see Non-Serverless storage expansion or Serverless storage expansion.

• For more information about RDS SQL Server storage shortages and solutions, see RDS SQL Server storage shortage issues.

Related APIs