ApsaraDB RDS:Change the storage type from local SSD to ESSD or general ESSD

Differences among local SSDs, ESSDs, and general ESSDs

Billing methods

When you change the storage type of an RDS instance, the fee varies based on the region in which your RDS instance resides and the instance specifications. You can view the fee when you perform the change.

Usage notes

• You can change the storage type of your RDS instance only from local SSD to ESSD or general ESSD. You cannot change the storage type of your RDS instance from ESSD or general ESSD to local SSD.

• The instance types that are supported by the local SSD and ESSD storage types are different. When you change the storage type of some RDS instances, you must change the instance type. For more information, see Instance types for standard primary ApsaraDB RDS for MySQL instances (original x86 architecture).

• The change operation is affected by various factors and may fail in some scenarios. For more information, see Which factors affect the time that is required to change the specifications of my ApsaraDB RDS for MySQL instance?

• When you change the storage type of your RDS instance from local SSD to ESSD, data is incrementally synchronized from the local SSD to the ESSD. However, if a large amount of data is being written to the local SSD, the ESSD may fail to fully synchronize with the local SSD. In this case, the change operation lasts for a long period of time. We recommend that you reduce the frequency of data writing during the change operation to speed up the change.

• Before you change the storage type, make sure that more than 10% of the storage capacity of the RDS instance is available. If the storage capacity is exhausted, the RDS instance is locked. For more information, see What do I do if an ApsaraDB RDS for MySQL instance is in the Locked state because its storage capacity is exhausted by data files?

Impacts

• The storage type change can trigger a migration of underlying data, which requires a period of time to complete. After the migration is complete, the system switches over your workloads at the specified switching time. During the switchover, a transient connection that lasts approximately 30 seconds occurs. We recommend that you change the storage type during off-peak hours and make sure that your application is configured to automatically reconnect to your RDS instance.

  Note

  After you change the storage type of an RDS instance, the endpoints of the RDS instance remain unchanged. You do not need to change the endpoints for your application.

• After you change the storage type of your RDS instance, you cannot use the backup sets that are generated before the change to restore the data of the RDS instance that uses general ESSDs or ESSDs. You can restore the data of the RDS instance by using only the backup sets that are generated after the change.

• When the storage type is being changed, you cannot perform specific operations on the RDS instance. For example, you cannot upgrade or downgrade the RDS instance, upgrade the database engine version of the RDS instance, or migrate the RDS instance across zones.

• After the storage type is changed from local SSD to ESSD or general ESSD, the cross-region backup feature for the RDS instance is automatically disabled due to differences in the underlying architectures of the storage types. We recommend that you reconfigure the cross-region backup policy for the RDS instance after the change is complete. This helps ensure that the cross-region backup feature can work as expected. For more information, see Use the cross-region backup feature.

Procedure

1. Go to the Instances page. In the top navigation bar, select the region in which the RDS instance resides. Then, find the RDS instance and click the ID of the instance.

2. In the Configuration Information section of the Basic Information page, click Change Specifications.

3. On the Change Instance Type page, select Storage Type. Select General ESSD, ESSD PL1, ESSD PL2, or ESSD PL3.

   Note

   • The following list describes the performance of ESSDs of different PLs:

     • The performance of ESSDs of different PLs is ranked in descending order: PL3 ESSD delivers the highest performance, followed by PL2 ESSD, and then PL1 ESSD.

     • A PL3 ESSD provides 20 times the IOPS and 11 times the throughput of a PL1 ESSD.

     • A PL2 ESSD delivers twice the IOPS and throughput of a PL1 ESSD.

   • The minimum storage capacities supported by PL1 ESSD, PL2 ESSD, and PL3 ESSD are 20 GB, 500 GB, and 1,500 GB.

   • The minimum storage capacity of a general ESSD is 10 GB.

   • General ESSDs deliver better baseline I/O performance than PL1 ESSDs and provide the I/O burst, I/O acceleration, and data archiving features. For more information, see What are general ESSDs?

4. Optional. Configure the Instance Type parameter.

   1. Select an instance family. You can select General-purpose or Dedicated.

      Instance type	Description	Benefit
      General-purpose	A general-purpose instance exclusively occupies the allocated memory and I/O resources. A general-purpose instance shares CPU and storage resources with the other general-purpose instances that are deployed on the same host.	A general-purpose instance is cost-effective.
      Dedicated	A dedicated instance exclusively occupies the allocated CPU, memory, storage, and I/O resources. Note The dedicated host instance family is the highest configuration of the dedicated instance family. A dedicated host RDS instance occupies all CPU, memory, storage, and I/O resources of the host on which the RDS instance is deployed.	A dedicated instance provides better performance and stability.

   2. Select an instance type.

      • In a test environment, select an instance type that provides 1 or more cores.

      • For a production environment, select an instance type that provides four or more cores.

      Note

      For more information about instance types, see Instance types for standard primary ApsaraDB RDS for MySQL instances (original x86 architecture).

5. Optional. Expand or reduce the storage capacity based on your business requirements.

   Note

   The storage capacity of the ESSD or general ESSD must be at least 1.2 times greater than the used storage of the local SSD of the RDS instance.

6. Configure the Switching Time parameter.

   • Execute Immediately

   • Switch Within Maintenance Window: The system switches your workloads over to the new RDS instance within the maintenance window that you specify. For more information, see Configure a maintenance window.

   Note

   • The switchover causes a transient connection that lasts approximately 30 seconds. We recommend that you change the storage type during off-peak hours and make sure that your application is configured to automatically reconnect to your RDS instance.

   • If you select Switch Within Maintenance Window, the RDS instance stays in the upgrading or downgrading state until the switchover is complete. During the switchover, you cannot perform specific operations on the RDS instance. For example, you cannot upgrade or downgrade the specifications of the RDS instance, upgrade the database engine version of the RDS instance, or migrate the RDS instance across zones.

7. Read and select the terms of service, click Pay Now, and then complete the payment.

   After the payment is complete, the status of the instance changes to Upgrading. When the instance status changes to Running, the change is complete.

FAQ

• Why am I unable to select the ESSD or general ESSD storage type for my RDS instance?

  If the zone in which your RDS instance resides cannot provide sufficient resources or does not support ESSDs or general ESSDs, you cannot select the ESSD or general ESSD storage type for your RDS instance. In this case, you must update the minor engine version of your RDS instance, migrate your RDS instance to a zone in which ESSDs or general ESSDs are supported, and then upgrade the storage type of your RDS instance to ESSD or general ESSD. For more information, see Update the minor engine version and Migrate an ApsaraDB RDS for MySQL instance across zones.

• Will online business be affected when I change the storage type of an RDS instance?

  For more information, see the "Impacts" section of this topic.

• Do the endpoints and IP addresses of my RDS instance change after I change the storage type?

  The endpoints of your RDS instance remain unchanged after you change the storage type. An example endpoint is rm-bpxxxxx.mysql.rds.aliyuncs.com. However, the IP addresses that are associated with the endpoints may change. We recommend that you add the endpoints to your application. Do not add the IP addresses to your application.

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