Updated on 2025-11-11 GMT+08:00

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 autoscale 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 .
  • The maximum allowed storage is 4,000 GB.
  • For a primary/standby DB instance, autoscaling the storage for the primary node will also autoscale the storage for the standby node.
  • Storage autoscaling is unavailable when the DB instance is in any of the following statuses: changing instance class, upgrading a minor version, migrating the standby DB instance, and rebooting.
  • If a yearly/monthly DB instance has pending orders, it will not be autoscaled.

Procedure

  1. Log in to the management console.
  2. Click in the upper left corner of the page and choose Databases > Relational Database Service.
  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) to go to the Overview page.
  4. In the Storage & Backup area, enable Storage Autoscaling.
  5. In the displayed dialog box, set the following parameters:

    Table 1 Parameter description

    Parameter

    Description

    Enable autoscaling

    If you select this option, autoscaling is enabled.

    Trigger If Available Storage Drops To

    If the available storage drops to a specified threshold (10%, 15%, or 20%) or 10 GB, autoscaling is triggered.

    Autoscaling Limit

    The default value range is from 40 GB to 4,000 GB. The limit must be no less than the storage of the DB instance.

  6. Click OK.