doc-exports/docs/rds/umn/rds_pg_scale_cluster.html

Scaling up Storage Space

Scenarios

If the original storage space is insufficient as your services grow, scale up storage space of your DB instance.

You are advised to set alarm rules for the storage space usage by referring to Setting Alarm Rules.

RDS allows you to scale up storage space of DB instances but you cannot change the storage type. During the scale-up period, services are not interrupted.

Instance Becomes Read-Only When Storage Is Full

For details about the causes and solutions of insufficient storage space, see What Should I Do If My Data Exceeds the Available Storage of an RDS DB Instance?

Table 1 Conditions under which an instance becomes read-only if it is out of storage

Storage Size	Condition
Any storage size	If the available storage space is less than 5 GB, the instance becomes read-only. NOTE: This rule takes precedence over other rules that can be used to set the instance read-only.
Storage size is less than 1 TB.	If the storage usage reaches 97%, the instance becomes read-only. If the storage usage decreases to 87%, the instance exits the read-only state.
Storage size is greater than or equal to 1 TB.	If the available storage space is less than 30 GB, the instance becomes read-only. If the available storage space is greater than or equal to 150 GB, the instance exits the read-only state.

Constraints

• The maximum allowed storage is 4,000 GB. There is no limit on the number of scale-ups.
• For primary/standby DB instances, scaling up the primary DB instance will cause the standby DB instance to also be scaled up accordingly.
• You cannot reboot or delete a DB instance that is being scaled up.
• Storage space can only be scaled up.
• If you scale up a DB instance with disks encrypted, the expanded storage space will be encrypted using the original encryption key.

Scaling up a Primary DB Instance

1. Log in to the management console.
2. Click in the upper left corner and select a region and a project.
3. Click Service List. Under Database, click Relational Database Service. The RDS console is displayed.
4. On the Instances page, locate the target DB instance and choose More > Scale Storage Space in the Operation column.

   You can also perform the following operations to scale up storage space:

   • Click the target DB instance to enter the Basic Information page. In the Storage Space area, click Scale.

5. On the displayed page, specify the new storage space and click Next.

   The minimum start value of each scaling is 10 GB. A DB instance can be scaled up only by a multiple of 10 GB. The allowed maximum storage space is 4,000 GB.

6. Confirm specifications.
   • If you need to modify your settings, click Previous.
   • If you do not need to modify your settings, click Submit.

7. View the scale-up result.

   Scaling up storage space takes 3-5 minutes. During the time period, the status of the DB instance on the Instances page will be Scaling up. Click the DB instance and view the utilization on the displayed Basic Information page to verify that the scale-up is successful.

Scaling up a Read Replica

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

1. Log in to the management console.
2. Click in the upper left corner and select a region and a project.
3. Click Service List. Under Database, click Relational Database Service. The RDS console is displayed.
4. On the Instances page, locate the target DB instance and click in front of it. Locate a read replica to be scaled and choose More > Scale Storage Space in the Operation column.

   You can also perform the following operations to scale up storage space:

   • Click the target DB instance to enter the Basic Information page. In the Storage Space area, click Scale.

5. On the displayed page, specify the new storage space and click Next.

   The minimum start value of each scaling is 10 GB. A read replica can be scaled up only by a multiple of 10 GB. The allowed maximum storage space is 4,000 GB.

6. Confirm specifications.
   • If you need to modify your settings, click Previous.
   • If you do not need to modify your settings, click Submit.

7. View the scale-up result.

   Scaling up storage space takes 3-5 minutes. During this time, the status of the read replica on the Instances page will be Scaling up. Click the read replica and view the utilization on the displayed Basic Information page to verify that the scale-up is successful.

Parent topic: Instance Modifications