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.

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

• To prevent workload 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.

1. Log in to the management console.
2. Click in the upper left corner and select a region and a project.
3. Click in the upper left corner of the page and choose Database > Relational Database Service.
4. On the Instances page, locate the target DB instance and choose More > Migrate Standby DB Instance in the Operation column.
5. Select the target AZ and click Submit.
6. 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 DB instance list, click to refresh the list. After the migration is complete, the DB instance status will become Available.
   • On the Basic Information page, find AZ and check the AZ hosting the standby DB instance.