Change the storage type from Premium Local SSD to cloud disk - ApsaraDB RDS

You can change the storage type of an ApsaraDB RDS for MySQL instance from Premium Local SSD to Premium ESSD or Enterprise SSD (ESSD) in the console for improved elasticity.

Prerequisites

The primary ApsaraDB RDS for MySQL instance runs one of the following versions:
- ApsaraDB RDS for MySQL 8.0 or 5.7 High-availability Edition with Premium Local SSD
Note
ApsaraDB RDS for MySQL 5.6 instances support only Premium Local SSDs. You cannot directly change the storage type of these instances to other cloud disk types. However, you can use alternative methods to achieve this. For more information, see the FAQ section.
The minor engine version of the instance is 20201031 or later. For information about how to upgrade the minor engine version, see Upgrade the minor engine version.
The instance does not have any read-only instances or disaster recovery instances.
The automatic performance scaling feature is not enabled for the instance.
The database proxy feature is not enabled for the instance.
The instance uses a VPC and does not have a classic network endpoint.
The instance does not use the IPv6 network protocol or connect to multiple VPCs. (This prerequisite applies only to specific scenarios.)
The instance is in the Running state.

Note

If your instance does not meet these prerequisites, you must create a new instance that uses Premium ESSDs or ESSDs and then migrate data from the original instance to the new one. For more information, see Migrate data between ApsaraDB RDS for MySQL instances.

Differences between high-performance local disks and cloud disks

Metric	Premium Local SSD	Premium performance disk	ESSD
I/O performance	★★★★★ Delivers low I/O latency and high I/O performance: IOPS: Varies based on the instance type. I/O latency: 10 to 50 microseconds	★★★★★★ Provides the Buffer Pool Extension (BPE) feature, I/O performance burst feature, and data archiving feature. The following list describes the I/O performance: IOPS: Varies based on the disk specifications and instance type. I/O latency: 100 to 200 microseconds	★★★★★ Delivers higher I/O performance than standard SSDs: IOPS: Varies based on the disk specifications and instance type. I/O latency: 100 to 200 microseconds
Configuration flexibility	★★★★ Provides various configuration options and lets you adjust the storage capacity separately. For some RDS instances that use Premium Local SSDs, the storage capacity is bound to the instance type and cannot be adjusted separately.	★★★★★ Provides various configuration options and lets you scale out or scale in the storage capacity of an RDS instance. Note Scale-in is supported only for MySQL instances that meet specific conditions. For more information, see Overview of instance changes and Change configuration.	★★★★★ Provides various configuration options and lets you scale out or scale in the storage capacity of an RDS instance. Note Scale-in is supported only for MySQL instances that meet specific requirements. For more information, see Overview of instance changes and Change the specifications of an ApsaraDB RDS instance.
Backup method	Physical backup using XtraBackup	Snapshot backup	Snapshot backup
Time required for backup, read-only instance creation, and instance cloning	★★★ Requires a few hours. The time varies based on the disk size.	★★★★★ Requires a few seconds.	★★★★★ Requires a few seconds.
Scale-out duration	★★★★ Requires a few hours to copy data.	★★★★★ Supports online scale-out. You can scale out the storage capacity of an RDS instance in seconds.	★★★★★ Supports online scale-out. You can scale out the storage capacity of an RDS instance in seconds.
Scale-out impact	Transient connection interruptions occur.	None.	None.
Data durability	★★★★ Hardware failures can cause data corruption. A secondary database is required. The SLA for High-availability Edition instances that use local disks is 99.995%.	★★★★★ Provides 99.9999999% data reliability and supports RDS instances that run RDS Basic Edition to reduce costs.	★★★★★ Provides 99.9999999% data reliability and supports RDS instances that run RDS Basic Edition to reduce costs.

Billing rules

The fee for changing the storage type varies based on the region where the instance is located and the selected configuration. The fee is displayed when you perform the change operation.

Usage notes

You can change the storage type only from Premium Local SSD to Premium ESSD or ESSD. You cannot reverse this change.
Premium Local SSDs and ESSDs support different instance types. When you change the storage type of some instances, you must also change the instance type. For more information about instance types, see ApsaraDB RDS for MySQL Standard Edition (formerly X86) primary instance specifications.
The change operation is affected by various factors and may fail in some cases. For more information, see Which factors affect the time required to change the specifications of my ApsaraDB RDS for MySQL instance?.
The change uses incremental data synchronization. If your application writes large amounts of data during the change, the target disk may fall behind the source disk. This may prevent the change from completing. To complete the change faster, reduce the data write frequency during the process.
Before you change the storage type, ensure that at least 10% of the disk space is free. If the disk becomes full, the instance is locked. For information about how to resolve this issue, see Resolve an ApsaraDB RDS for MySQL instance locked due to storage exhaustion by data files.

Impacts

Changing the storage type may trigger an underlying data migration. After the migration is complete, the system automatically switches over your workloads at the specified time. During the switchover, a transient disconnection that lasts about 15 seconds occurs. We recommend that you perform the change during off-peak hours and ensure that your application supports automatic reconnection.
Note
Changing the storage type does not change the instance endpoints. You do not need to update them in your application.
After the change, you cannot use backup sets created before the change to restore the instance. You must use backup sets created after the change for restoration.
While the storage type is being changed, you cannot perform instance-level operations such as upgrading or downgrading the instance, upgrading the database engine version, or migrating the instance across zones.
Because of architectural differences between storage types, changing from Premium Local SSD to Premium ESSD or ESSD automatically disables the cross-region backup feature. After the change, you must reconfigure the cross-region backup policy to ensure continued functionality. For more information, see Cross-region backup.

Procedure

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.
In the Basic Information section, click Configuration Information. Then, click Change Specifications on the right.
On the Change Instance Specifications page, you can set Storage Type to Premium ESSD or ESSD (PL1, PL2, or PL3).
In some zones, resources may be insufficient or cloud disks may be unavailable for purchase. In this case, the option to change the storage type to a cloud disk is unavailable. You must migrate the instance to a zone where cloud disks are available, and then change the storage type. For more information, see Migrate an ApsaraDB RDS for MySQL instance across zones.
Note
- ESSD performance levels (PLs):
  Performance ranking: PL3 > PL2 > PL1.
  A PL3 ESSD delivers up to 20 times the IOPS and 11 times the throughput of a PL1 ESSD.
  A PL2 ESSD delivers up to twice the IOPS and throughput of a PL1 ESSD.
- The minimum disk space requirements differ: PL3 requires 1,500 GB, PL2 requires 500 GB, and PL1 requires 20 GB.
- The minimum disk space for a Premium ESSD is 10 GB.

You can optionally set the Instance Type.

You can select Classification: General-purpose or Dedicated.

Classification

Description

Features

General-purpose instance type

Exclusively uses memory and I/O resources.

Shares CPU and storage resources with other general-purpose instances on the same host.

Cost-effective.

Dedicated instance type

Exclusively uses CPU, memory, storage, and I/O resources.

Note

Dedicated host instances are the highest configuration of dedicated instances. They exclusively use all CPU, memory, storage, and I/O resources of their host.

Better performance and stability.

Select a specific instance type based on the number of CPU cores and memory size.
- For test environments: Choose an instance type with one or more CPU cores.
- For production environments: Choose an instance type with four or more CPU cores.
Note
For more information about instance types, see ApsaraDB RDS for MySQL Standard Edition (formerly X86) primary instance specifications.

Optional: You can increase or decrease the Storage Capacity as needed.
Note
The storage capacity of the cloud disk must be at least 1.2 times the used space of the original Premium Local SSD.
Set Switching Time. This is the scheduled time for the primary/secondary switchover after the storage type upgrade.
- Execute Immediately
- Switch Within Maintenance Window: The system performs the switchover during your maintenance window.
Note
- The switchover causes a transient disconnection that lasts about 15 seconds. We recommend that you perform the change during off-peak hours and ensure that your application supports automatic reconnection.
- If you select Switch Within Maintenance Window, the instance enters the Upgrading or Downgrading state until the switchover is complete. While the instance is in this state, you cannot perform instance-level operations, such as upgrading or downgrading the instance, upgrading the database engine version, or migrating the instance across zones.
Read and accept the terms of service. Then click Pay Now to complete your payment.
After you complete the payment, the instance status changes to Upgrading or Downgrading. When the status changes to Running, the configuration change is complete.

FAQ

How do I change the storage type of an ApsaraDB RDS for MySQL 5.6 instance from Premium Local SSD to ESSD or Premium ESSD?

You cannot directly change the storage type of ApsaraDB RDS for MySQL 5.6 instances because they support only Premium Local SSDs. Use the following steps instead:

Upgrade the major engine version.
On the instance details page, go to the Major Version Upgrade page and click Create upgrade check report. After the check is complete, click Upgrade Instance to upgrade your MySQL 5.6 Premium Local SSD instance to MySQL 5.7 or 8.0 Premium Local SSD. For more information, see Benefits of upgrading from MySQL 5.6 to MySQL 5.7.
Change the storage type.
On your instance's Basic Information page, click Change Specifications to change the storage type from Premium Local SSD to ESSD or Premium ESSD for MySQL 5.7 or 8.0.

Why can I not select Premium ESSD or ESSD as the storage type?

In some zones, resources may be insufficient or cloud disks may be unavailable for purchase. If the instance is in such a zone, you must migrate it to a zone where cloud disks are available, and then change the storage type to a cloud disk. For more information, see Migrate an ApsaraDB RDS for MySQL instance across zones.

Does changing the storage type affect online workloads?

For more information, see Impacts.

Do the endpoints of the instance change after the storage type is changed?

The endpoints of the instance, such as rm-bpxxxxx.mysql.rds.aliyuncs.com, remain unchanged. However, the associated IP addresses may change. We recommend that you use the endpoints instead of the IP addresses in your application.

Related API operations

API	Description
ModifyDBInstanceSpec	Changes instance specifications.