Updated on 2026-04-24 GMT+08:00

Buying an RDS for SQL Server Instance

Scenarios

This section describes how to create a DB instance on the RDS console.

RDS for SQL Server supports pay-per-use billing. It allows you to choose compute resources and storage that fit your business needs.

Procedure

  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, click Buy DB Instance.
  5. On the Buy DB Instance page, set instance information and click Buy Now.

    • Basic settings
      Table 1 Basic settings

      Parameter

      Description

      Region

      Region where your resources are located.

      NOTE:

      Products in different regions cannot communicate with each other through a private network. After a DB instance is created, the region cannot be changed. Therefore, exercise caution when selecting a region.

      DB Instance Name

      Must start with a letter and consist of 4 to 64 characters. Only letters (case-sensitive), digits, hyphens (-), and underscores (_) are allowed.

      • If you intend to create multiple DB instances and read replicas at a time, the allowed length for each instance name will change.
      • If you buy multiple DB instances at a time, their names will include a four-digit suffix. For example, if you specify instance here, the names will be instance-0001, instance-0002, and so on. If existing instances' suffixes have already reached up to 0010, the new instance names will start from instance-0011.

      DB Engine

      Select Microsoft SQL Server.

      DB Engine Version

      For details, see DB Engines and Versions.

      Supported DB engine versions may vary by region. For the actual options, see them on the console.

      For RDS for SQL Server, select an appropriate DB engine version tailored to your workloads. You are advised to select the latest available version because it is more stable, reliable, and secure.

      DB Instance Type

      • Primary/Standby: uses an HA architecture with a primary DB instance and a synchronous standby DB instance. It is suitable for production databases of large- and medium-sized enterprises in Internet, Internet of Things (IoT), retail e-commerce sales, logistics, gaming, and other sectors. When a primary instance is being created, a standby instance is provisioned along with it to provide data redundancy. The standby instance is invisible to you after being created.
      • Single: uses a standalone architecture, which is less expensive than primary/standby DB instances. It is recommended for development and testing of microsites, and small and medium enterprises, or for learning about RDS.

      AZ

      An AZ is a physical region where resources use independent power supplies and networks. AZs are physically isolated but interconnected through an internal network.

      To achieve high reliability, RDS will automatically deploy your primary and standby instances in different physical servers even if you deploy them in the same AZ. If you attempt to deploy your primary and standby instances in the same AZ in a Dedicated Computing Cluster (DCC) and there is only one physical server available, the creation will fail.

      You can deploy your primary and standby instances in a single AZ or across AZs to implement failover and high availability.

      Storage Type

      Determines the instance read/write speed. A higher maximum throughput enables faster I/O operations.

      Ultra-high I/O: uses the SSD disk type that supports a maximum throughput of 350 MB/s.

      Time Zone

      Select a time zone based on the region your instance will be hosted in. After an instance is created, the time zone cannot be modified.

      Character Set

      Defines a collation of a database or table column, or a collation cast operation when applied to character string expression. It acts as the default collation for the DB instance.

    • Specifications and storage
      Table 2 Specifications and storage

      Parameter

      Description

      Instance Class

      Refers to the vCPU and memory of a DB instance. Different instance classes support different numbers of database connections and maximum IOPS.

      For details about instance classes, see RDS for SQL Server Instance Classes.

      After a DB instance is created, you can change its instance class. For details, see Changing a DB Instance Class.

      Storage Space

      Contains the system overhead required for inodes, reserved blocks, and database operation. Storage space can range in size from 40 GB to 4,000 GB and can be scaled up only by a multiple of 10 GB.

      After a DB instance is created, you can scale up its storage space. For details, see Scaling Up Storage Space.

      Disk Encryption

      • Disable: Encryption is disabled.
      • Enable: Encryption is enabled, which improves data security but affects system performance.

        If you select this option, the Key Name parameter appears. Select an existing key or create a new one as the tenant key.

        NOTE:
        • If you enable disk encryption during instance creation, the disk encryption status and the key cannot be changed later. Disk encryption will not encrypt backup data stored in OBS buckets.
        • If disk encryption is enabled, keep the key secure. Once the key is disabled, deleted, or frozen, your instance will be inaccessible and data may not be restored.
        • For details about how to create a key, see "Creating a CMK" in Data Encryption Workshop User Guide.
    • Network and database configurations
      Table 3 Network

      Parameter

      Description

      VPC

      A virtual network in which your RDS instances are located. A VPC can isolate networks for different workloads. You can select an existing VPC or create a VPC. For details about how to create a VPC, see "Creating a VPC" in Virtual Private Cloud User Guide.

      If no VPC is available, RDS allocates a VPC to you by default.

      NOTICE:

      After a DB instance is created, the VPC cannot be changed.

      Subnet

      Improves network security by providing dedicated network resources that are logically isolated from other networks. Subnets are only valid within a specific AZ. Dynamic Host Configuration Protocol (DHCP) is enabled by default for subnets where you plan to create DB instances and cannot be disabled.

      A floating IP address is automatically assigned when you create an RDS instance. You can also enter an unused floating IP address in the subnet CIDR block. After the DB instance is created, the floating IP address cannot be changed.

      • IPv4 address:

        A floating IPv4 address is automatically assigned when you create a DB instance. You can also enter an unused floating IPv4 address in the subnet CIDR block. After the DB instance is created, you can change the floating IP address.

      Security Group

      Enhances security by controlling access to RDS from other services. Ensure that the security group you select allows the client to access the DB instance.

      When creating a DB instance, you can select multiple security groups. For better network performance, select no more than five security groups. If you select more than one security group, the access rules of all the selected security groups apply on the instance.

      If no security group is available, RDS allocates a security group to you by default.

      Table 4 Database configuration

      Parameter

      Description

      Administrator

      The default login name for the database is rdsuser.

      Administrator Password

      The new password must consist of 8 to 32 characters and contain at least three types of the following characters: uppercase letters, lowercase letters, digits, and special characters (~!@#$%^*-_+?,). Enter a strong password and periodically change it for security reasons.

      If the password you provide is considered weak by the system, you will be prompted to provide a stronger password.

      Keep this password secure. The system cannot retrieve it.

      After a DB instance is created, you can reset this password. For details, see Resetting the Administrator Password.

      Confirm Password

      Must be the same as Administrator Password.

      Parameter Template

      Contains engine configuration values that can be applied to one or more DB instances of the same DB engine. If you intend to create a primary/standby DB pair, they use the same parameter template. You can modify the instance parameters as required after the DB instance is created.

      NOTICE:

      If you use a custom parameter template when creating a DB instance, the specification-related parameter max server memory (MB) in the custom template is not delivered. Instead, the default value is used.

      After an instance is created, you can adjust its parameters as needed. For details, see Modifying RDS for SQL Server Instance Parameters.

      Enterprise Project

      If your account has been associated with an enterprise project, select the target project from the Enterprise Project drop-down list.

    • Tags
      Table 5 Tag

      Parameter

      Description

      Tag

      Tags an RDS instance. This parameter is optional. Adding tags to RDS instances helps you better identify and manage the instances. Up to 20 tags can be added for each DB instance.

      If your organization has configured tag policies for RDS, add tags to DB instances based on the policies. If any tag you add does not comply with the policies, DB instance creation may fail. Contact your organization administrator to learn more about tag policies.

      After a DB instance is created, you can view its tag details on the Tags page. For details, see RDS for SQL Server Tags.

    • Batch creation
      Table 6 Batch creation

      Parameter

      Description

      Quantity

      RDS supports DB instance creation in batches. If you choose to create primary/standby DB instances and set Quantity to 1, a primary DB instance and a standby DB instance will be created synchronously.

      If you create multiple DB instances at a time, their names will include a four-digit suffix. For example, if you specify instance here, the names will be instance-0001, instance-0002, and so on. If existing instances' suffixes have already reached up to 0010, the new instance names will start from instance-0011.

    The performance of your RDS instance depends on its configurations. The hardware configuration items you can choose include the instance class, storage type, and storage space.

  6. Confirm the instance specifications.

    • If you need to modify your settings, click Previous.
    • If you do not need to modify your settings, click Submit.

  7. To view and manage your instance, go to the Instances page.

    • When your DB instance is being created, the status is Creating. The status changes to Available after the instance is created.
    • The system automatically enables an automated backup policy for the instance during creation. You can modify the policy, if needed, after the instance is created. The system automatically creates a full backup once an instance is created.
    • After a DB instance is created, you can enter a description for it.
    • The default database port is 1433. You can change it after a DB instance is created.

      For details, see Changing a Database Port.