All Products
Search

This Product

    ApsaraDB RDS:Change specifications

    Document Center

    ApsaraDB RDS:Change specifications

    Last Updated:Oct 08, 2026

    This topic describes how to change the specifications of a standard ApsaraDB RDS for SQL Server instance, such as the performance level (PL) of its storage type (for example, from ESSD PL1 to ESSD PL2), its instance type, and its storage capacity. You can change specifications to improve instance performance and resolve storage bottlenecks caused by business growth. After you change the specifications, you do not need to manually restart the instance. Additionally, some instances support seamless storage capacity expansion without interrupting database access.

    Note

    For information about how to change the specifications of a serverless ApsaraDB RDS for SQL Server instance, see Change the scaling range of RCUs and Increase storage capacity.

    Changes

    Changing the following specifications does not change the endpoint of the instance. To scale out the read capacity of your database, you can create a read-only instance and configure read/write splitting to offload the primary instance. The primary instance must be a Cluster Edition instance.

    Item

    Description

    Version

    You can upgrade the database engine version to a later version.

    Edition

    You can upgrade from Basic Edition to High-availability Edition or Cluster Edition, or from High-availability Edition to Cluster Edition.

    Instance type

    • If the instance family remains unchanged and you only need to change the specification code: You can use the Change Specifications entry point.

      For example, if the instance family is general-purpose, you can change the instance type from mssql.s2.medium.s2 to mssql.s2.large.s2.

    • To change the instance family: You can use the Upgrade Version entry point to change to an instance of the same or a higher-tier family, except in some cases. The console shows all available options. The instance families are ranked from low to high: Shared < General-purpose < Dedicated. Downgrading to a lower-tier instance family is not supported.

      For example, you can change the instance family from general-purpose to dedicated.

      Note

      • If your instance runs RDS High-availability Edition and uses a shared instance type, you cannot upgrade it directly to a dedicated instance type on RDS Cluster Edition.

      • If the target instance family is not shown in the console, create a new instance with the required family and migrate data to it.

    Storage type

    • For instances that use ESSDs, you can upgrade the PL. Downgrading the PL is not supported. For example, you can upgrade from ESSD PL1 to ESSD PL2.

    • For non-Cluster Edition instances, you can upgrade the storage type from standard SSD to ESSD. You cannot downgrade the storage type from ESSD to standard SSD.

      Note

      You cannot upgrade the storage type of Cluster Edition instances from standard SSD to ESSD. However, you can create a new instance that uses an ESSD and then migrate the data from the original instance to the new instance.

    Storage capacity

    • You can only increase the storage capacity. Decreasing the storage capacity is not supported.

    • When you increase the storage capacity, the minimum increment is 5 GB. The total storage capacity cannot exceed the storage capacity limit of the current instance type.

    Note

    • A read-only instance's storage capacity cannot be smaller than its primary instance's. Therefore, you must first increase the storage capacity of the read-only instances before you increase the storage capacity of the primary instance.

    • If the storage capacity range of the current instance type does not meet your requirements, select a different instance type.

    Prerequisites

    Your Alibaba Cloud account has no unpaid renewal orders.

    Usage notes

    • A specification change, such as a major version upgrade, may involve a cross-host migration. This process deletes host accounts and any programs or files, such as SQL Server Integration Services (SSIS), SQL Server Analysis Services (SSAS), or SQL Server Reporting Services (SSRS), that are deployed on the original host. Make sure you migrate or back up your data in advance.

      Important

      ApsaraDB RDS for SQL Server is built on the native Microsoft SQL Server engine and focuses on providing stable and efficient managed database services. If your business requires features such as SSIS, SSAS, or SSRS, you need strong operations expertise to ensure business continuity.

    • Changing specifications may trigger data migration. After the migration is complete, the system performs a switchover at your selected switchover time. Incremental data is synchronized during this period. The switchover causes a brief interruption that lasts for about 30 seconds. During this period, you cannot perform most operations related to the database, accounts, or network. We recommend that you perform the operation during off-peak hours and make sure that your application has an automatic reconnection mechanism.

    • Basic Edition provides only a single database node with no secondary node for hot backup. Therefore, the node may be unavailable for an extended period if it unexpectedly fails or undergoes tasks such as a specification change or version upgrade. If your business requires high database availability, we recommend that you do not use Basic Edition. Instead, select another edition, such as High-availability Edition.

    • If a primary instance has read-only instances, you must ensure that the storage capacity of each read-only instance is greater than or equal to that of the primary instance before you expand the storage of the primary instance. We recommend expanding the storage capacity of all read-only instances before expanding that of the primary instance.

    Billing

    For more information, see Billing for specification changes.

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

    3. (This step is required only for subscription instances.) In the dialog box that appears, select a change method (Upgrade or Downgrade: The new specifications take effect immediately) and click Next.

      After the change task is submitted, the system synchronizes data to a new instance. Then, at the scheduled switchover time, the system assigns the original instance ID and endpoint to the new instance. The instance ID and endpoint remain unchanged.

    4. Modify the specifications of the instance. For more information, see Changes.

      Important

      • Some ApsaraDB RDS for SQL Server instances support seamless storage capacity expansion. When you only change the PL of the storage type (for example, from ESSD PL1 to ESSD PL2) or expand the storage capacity, your database access is not interrupted. Therefore, you do not need to set a switchover time. However, if you also change the instance type, you must configure a switchover time.

      • If you have not changed any specifications but the Change Specifications page still displays the Switchover time option, your RDS instance does not support seamless storage capacity expansion. You can upgrade the major or minor engine version of your instance and then change specifications to enable seamless storage capacity expansion.

    5. Select when to apply the new specifications.

      • Switch Immediately After Data Migration: The switchover occurs as soon as data migration finishes.

      • Switch Within Maintenance Window: The switchover occurs during your configured maintenance window to minimize disruption.

      Note

      • Some instances support seamless storage capacity expansion. For these instances, this setting is not displayed, and you do not need to configure a switchover time.

      • If you select Switch Within Maintenance Window, regular backups for the instance are disabled during the specification change process.

    6. On the Change Specifications page, confirm the specifications of the instance before and after the change, click Confirm Order, and then complete the payment.

      Warning

      • After you submit a configuration change order, you cannot cancel it. We recommend that you carefully evaluate your business requirements before you proceed.

      • To ensure a successful configuration change, do not perform any Data Definition Language (DDL) operations from the time you submit the order until the change is complete.

    FAQ

    Does changing the PL of the storage type interrupt database access?

    • Some ApsaraDB RDS for SQL Server instances support seamless storage capacity expansion. When you only change the PL of the storage type (for example, from ESSD PL1 to ESSD PL2) or expand the storage capacity, your database access is not interrupted. Therefore, you do not need to set a switchover time. However, if you also change the instance type, you must configure a switchover time.

    • If you have not changed any specifications but the Change Specifications page still displays the Switchover time option, your RDS instance does not support seamless storage capacity expansion. You can upgrade the major or minor engine version of your instance and then change specifications to enable seamless storage capacity expansion.

    Can I change the zone and version?

    • For instances that do not run SQL Server 2008 R2: You can call the ModifyDBInstanceSpec API operation to upgrade the major database version and change the zone and vSwitch of the instance. You can also upgrade the major database version in the ApsaraDB RDS console.

    • For instances that run SQL Server 2008 R2 with high-performance local disks: You can use the ApsaraDB RDS console to upgrade the version and change the zone at the same time.

    Note

    You can also migrate the zone separately.

    If I only expand the storage capacity, do I need to migrate data to a new instance?

    No. The system handles this automatically, and you do not need to manually migrate data. When you expand storage, the system checks if the current host has enough space. If so, the capacity is expanded in place. If not, the system automatically migrates your data to a host with sufficient space.

    How long does a specification change take?

    In 90% of cases, a specification change completes within 30 minutes.

    If I upgrade the CPU, memory, and disk at the same time, how long will the brief interruption last?

    The duration of the brief interruption is the same regardless of whether you upgrade the CPU, memory, and storage capacity separately or at the same time. The interruption typically lasts for about 30 seconds. During the switchover, a service interruption or instance restart may occur. Most operations on the database, accounts, and network are unavailable during this period. We recommend that you perform the specification change within the specified maintenance window. For more information about the changeable items, see Changes.

    Related API

    Use the ModifyDBInstanceSpec API to change the specifications and storage capacity of an RDS instance