You can change the storage type of an ApsaraDB RDS for MySQL instance from Premium Local SSD to Premium Enhanced SSD (ESSD) or standard ESSD. This change is irreversible — once completed, you cannot revert to a Premium Local SSD.
Storage type comparison
| Metric | Premium Local SSD | Premium ESSD | ESSD |
|---|---|---|---|
| I/O performance | IOPS varies by instance type. I/O latency: 10–50 microseconds | IOPS varies by disk spec and instance type. I/O latency: 100–200 microseconds. Includes Buffer Pool Extension (BPE), I/O performance burst, and data archiving features | IOPS varies by disk spec and instance type. I/O latency: 100–200 microseconds |
| Configuration flexibility | Various options available. For some instance types, storage capacity is tied to instance type and cannot be adjusted separately | Scale out or scale in storage capacity independently. Scale-in requires specific conditions (see Overview of instance changes and Change configuration) | Scale out or scale in storage capacity independently. Scale-in requires specific conditions (see Overview of instance changes and Change the specifications of an ApsaraDB RDS instance) |
| Backup method | Physical backup (XtraBackup) | Snapshot backup | Snapshot backup |
| Backup, cloning, and read-only instance creation | A few hours, depending on disk size | Seconds | Seconds |
| Scale-out duration | A few hours; data must be copied | Online, in seconds | Online, in seconds |
| Scale-out impact | Transient connection interruption | None | None |
| Data durability | 99.995% SLA (High-availability Edition). Hardware failures can cause data corruption; a secondary database is required | 99.9999999% | 99.9999999% |
Billing
The fee depends on the region and the specifications you select. You can view the fee during the configuration change process.
Prerequisites
Before you begin, make sure that:
Your instance runs ApsaraDB RDS for MySQL 8.0 or 5.7 on High-availability Edition with Premium Local SSDs
MySQL 5.6 instances support only Premium Local SSDs and cannot be directly migrated to cloud disks. See the FAQ for the workaround.
The minor engine version is 20201031 or later. To upgrade, see Upgrade the minor engine version
The instance has no read-only instances or disaster recovery instances
Automatic performance scaling is disabled
The database proxy is disabled
The instance uses a Virtual Private Cloud (VPC) and has no classic network endpoint
The instance does not use IPv6 and is not connected to multiple VPCs (applies to special scenarios only)
The instance is in the Running state
At least 10% of disk space is free. If the disk is full, the instance becomes locked — see Resolve a locked instance due to storage exhaustion
If your instance does not meet these prerequisites, create a new instance with Premium ESSD or standard ESSD and migrate your data. See Migrate data between ApsaraDB RDS for MySQL instances.
Potential impacts
Brief downtime during switchover. The change triggers incremental data synchronization followed by a primary/secondary switchover. The switchover causes a transient disconnection lasting about 15 seconds. Schedule the change during off-peak hours and make sure your application has automatic reconnection configured.
The connection endpoint (for example, rm-bpxxxxx.mysql.rds.aliyuncs.com) does not change. The associated IP addresses may change — use endpoints in your application, not IP addresses.
Old backups cannot restore the upgraded instance. Backup sets created before the change cannot be used to restore the instance after it uses Premium ESSD or standard ESSD. Only backups created after the change are valid for restoration.
Instance-level operations are blocked during the change. While the storage type is being changed (or while the instance is waiting for the switchover window), you cannot upgrade or downgrade the instance, upgrade the database engine version, or migrate across zones.
Cross-region backup is disabled. Switching from a Premium Local SSD to a cloud disk automatically disables the full cross-region backup feature due to differences in the underlying storage architecture. After the change, reconfigure your cross-region backup policy. See Enable cross-region backup for an ApsaraDB RDS for MySQL instance.
Usage notes
This change is irreversible. You can only change from Premium Local SSD to Premium ESSD or standard ESSD — not in the other direction.
Some instance types are not available for cloud disks. If your current instance type is incompatible, you must also select a new instance type during the change. For supported types, see Primary ApsaraDB RDS for MySQL instances.
The change uses incremental data synchronization. Heavy write activity during the change may cause synchronization to fall behind, which can prevent the change from completing. Reduce write frequency during the process.
Go to the Instances page. In the top navigation bar, select the region where your RDS instance resides. Find the instance and click its ID.
In the Basic Information section, click Configuration Information, then click Change Specifications on the right.
On the Change Instance Type page, set Storage Type to Premium ESSD or ESSD (PL1, PL2, or PL3). If cloud disks are unavailable in your zone due to resource constraints, migrate the instance to a zone where cloud disks are available and then retry.
- ESSD performance levels: 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. - Minimum disk space: PL1 = 20 GB, PL2 = 500 GB, PL3 = 1,500 GB. - Minimum disk space for a Premium ESSD: 10 GB.
(Optional) Select a new instance type if the current type is not supported for cloud disks.
For Classification, select General-purpose or Dedicated.
Classification Resources Suitable for General-purpose Exclusively uses memory and I/O; shares CPU and storage Cost-effective Dedicated Exclusively uses CPU, memory, storage, and I/O Performance-critical workloads Note: A dedicated host instance exclusively uses all CPU, memory, storage, and I/O resources of its physical host — the highest configuration in the Dedicated family.
Select an instance type based on CPU cores and memory: For the full list of supported types, see Primary ApsaraDB RDS for MySQL instances.
Test environments: 1 or more CPU cores
Production environments: 4 or more CPU cores
(Optional) Adjust storage capacity as needed.
The cloud disk storage capacity must be at least 1.2 times the used storage space of the original Premium Local SSD.
Select the Switching Time — when the primary/secondary switchover occurs after data synchronization completes.
Execute Immediately: The switchover happens as soon as synchronization finishes.
Switch Within Maintenance Window: The switchover occurs during the configured maintenance window. The instance remains in the Upgrading state until the switchover completes, during which instance-level operations are unavailable.
Accept the terms of service and click Pay Now to complete payment.
The instance status changes to Upgrading. When it returns to Running, the change is complete. No further action is required while the instance is upgrading.
FAQ
How do I change the storage type of a MySQL 5.6 instance to ESSD or Premium ESSD?
MySQL 5.6 instances support only Premium Local SSDs, so a direct storage type change is not possible. First upgrade the major engine version:
Upgrade the major engine version to MySQL 5.7 or 8.0. On the instance details page, go to Major Version Upgrade, click Create upgrade check report, and then click Upgrade Instance. See Benefits of upgrading MySQL 5.6 to MySQL 5.7 for details.
After the upgrade, follow the steps in this topic to change the storage type on the Basic Information page of your MySQL 5.7 or 8.0 instance.
Why can't I select Premium ESSD or standard ESSD as the storage type?
Some zones temporarily stop selling cloud disks or have insufficient resources. Migrate your instance to a zone where cloud disks are available, then retry the storage type change.
Does the change affect my running application?
A transient disconnection of about 15 seconds occurs during the final switchover. The connection endpoint does not change, so no application reconfiguration is needed. See Potential impacts for full details.
Do my endpoints or IP addresses change after the storage type change?
Endpoints (for example, rm-bpxxxxx.mysql.rds.aliyuncs.com) remain unchanged. Associated IP addresses may change. Use endpoints in your application code rather than IP addresses.
API reference
| API | Description |
|---|---|
| ModifyDBInstanceSpec | Changes instance specifications |