Changing the AZ of a Standby DB Instance

You can migrate a standby DB instance to another AZ in the same region as the original AZ.

For details about regions and AZs, see Regions and AZs.

Only when a DB instance is available and its storage is not full, you can migrate its standby instance to another AZ.

To prevent service interruption, perform the operation during off-peak hours.
Before the migration, check the resource usage of your DB instance to prevent resource overload from affecting workloads and the migration progress.
During the migration, if there is a large amount of data being written to the primary instance (in synchronous replication mode), the write operations may be blocked after the migration.
After the migration, check your workloads and verify data.
The migration duration is in direct proportion to the instance data volume.

Log in to the RDS console.
Click in the upper left corner and select a region.
On the Instances page, locate the target DB instance and choose More > Migrate Standby Instance to Another AZ in the Operation column.
On the displayed page, select a target AZ and click Submit.
Check the DB instance status on the Instances page.
- During the migration process, the DB instance status is Migrating standby DB instance. You can view the progress on the Task Center page. For details, see Task Center.
- In the upper right corner of the instance list, click to refresh the list. After the migration is complete, the instance status becomes Available.
- On the Summary page, find AZ and check the AZ hosting the standby DB instance.