Configuring Storage Autoscaling

Scenarios

With storage autoscaling enabled, when RDS detects that you are running out of database space, it automatically scales up your storage.

Autoscaling up the storage space of a read replica does not affect that of the primary DB instance. Therefore, you can separately configure autoscaling for read replicas to meet service requirements. New storage space of read replicas after autoscaling up must be greater than or equal to that of the primary DB instance.

Constraints

• You can enable storage autoscaling only when your account balance is greater than or equal to $0 USD.
• The storage space can be scaled up automatically only when your instance status is Available or Storage full.
• The maximum allowed storage is 10,000 GB. It varies depending on the storage type.
• For primary/standby DB instances, autoscaling the storage for the primary DB instance will also autoscale the storage for the standby DB instance.
• Storage autoscaling is unavailable when the DB instance is changing instance class or rebooting.
• If a yearly/monthly DB instance has pending orders, it will not autoscale.
• There is an upper limit for storage autoscaling. A maximum of two scale-ups are allowed within one hour and a maximum of five scale-ups within one day. If an instance undergoes multiple scale-ups within a short period due to a sharp increase in temporary databases or log files, you can perform a shrink operation to reduce storage usage.
• Storage autoscaling takes 1 to 2 minutes. If the write rate is excessively high during a scale-up, storage may become full, which will affect your workload. If a DB instance has small storage capacity, you are advised to set a higher value for the threshold Trigger If Available Storage Drops To.

Procedure

1. Log in to the RDS console.
2. Click in the upper left corner and select a region.
3. On the Instances page, click the target DB instance or read replica name (click in front of a DB instance to locate its read replica).
4. In the Storage & Backup area, toggle on the Storage Autoscaling switch.
   Figure 1 Storage space
   

5. In the displayed dialog box, set the following parameters.
   Figure 2 Configuring autoscaling
   

   Table 1 Parameter description

   Parameter	Description
   Enable Storage Autoscaling	If you turn the toggle switch on, autoscaling is enabled.
   Trigger If Available Storage Drops To	If the available storage drops to a specified threshold or 10 GB, autoscaling is triggered.
   Autoscaling Limit	The value range is from 40 to 10,000, in GB. The limit must be no less than the storage of the DB instance.

6. Click OK.