Tutorial: Migrate SQL Server to an Azure SQL Managed Instance online by using Azure Data Studio with DMS

Use the Azure SQL migration extension in Azure Data Studio to migrate database(s) from a SQL Server instance to an Azure SQL Managed Instance with minimal downtime. For methods that might require some manual effort, see the article SQL Server instance migration to Azure SQL Managed Instance.

In this tutorial, you migrate the AdventureWorks database from an on-premises instance of SQL Server to Azure SQL Managed Instance with minimal downtime by using Azure Data Studio with Azure Database Migration Service (DMS). This tutorial focuses on the online migration mode where application downtime is limited to a short cutover at the end of the migration.

In this tutorial, you learn how to:

  • Launch the Migrate to Azure SQL wizard in Azure Data Studio
  • Run an assessment of your source SQL Server database(s)
  • Collect performance data from your source SQL Server
  • Get a recommendation of the Azure SQL Managed Instance SKU best suited for your workload
  • Specify details of your source SQL Server, backup location and your target Azure SQL Managed Instance
  • Create a new Azure Database Migration Service and install the self-hosted integration runtime to access source server and backups
  • Start and monitor the progress for your migration
  • Perform the migration cutover when you are ready

Important

Prepare for migration and reduce the duration of the online migration process as much as possible to minimize the risk of interruption caused by instance reconfiguration or planned maintenance. In case of such an event, migration process will start from the beginning. In case of planned maintenance, there is a grace period of 36 hours where the target Azure SQL Managed Instance configuration or maintenance will be held before migration process is restarted.

Tip

In Azure Database Migration Service, you can migrate your databases offline or while they are online. In an offline migration, application downtime starts when the migration starts. To limit downtime to the time it takes you to cut over to the new environment after the migration, use an online migration. We recommend that you test an offline migration to determine whether the downtime is acceptable. If the expected downtime isn't acceptable, do an online migration.

This article describes an online database migration from SQL Server to Azure SQL Managed Instance. For an offline database migration, see Migrate SQL Server to a SQL Managed Instance offline using Azure Data Studio with DMS.

Prerequisites

To complete this tutorial, you need to:

  • Download and install Azure Data Studio

  • Install the Azure SQL migration extension from the Azure Data Studio marketplace

  • Have an Azure account that is assigned to one of the built-in roles listed below:

    • Contributor for the target Azure SQL Managed Instance (and Storage Account to upload your database backup files from SMB network share).
    • Reader role for the Azure Resource Groups containing the target Azure SQL Managed Instance or the Azure storage account.
    • Owner or Contributor role for the Azure subscription (required if creating a new DMS service).
    • As an alternative to using the above built-in roles you can assign a custom role as defined in this article.

    Important

    Azure account is only required when configuring the migration steps and is not required for assessment or Azure recommendation steps in the migration wizard.

  • Create a target Azure SQL Managed Instance.

  • Ensure that the logins used to connect the source SQL Server are members of the sysadmin server role or have CONTROL SERVER permission.

  • Use one of the following storage options for the full database and transaction log backup files:

    • SMB network share
    • Azure storage account file share or blob container

    Important

    • If your database backup files are provided in an SMB network share, Create an Azure storage account that allows the DMS service to upload the database backup files. Make sure to create the Azure Storage Account in the same region as the Azure Database Migration Service instance is created.
    • Azure Database Migration Service does not initiate any backups, and instead uses existing backups, which you might already have as part of your disaster recovery plan, for the migration.
    • You need to take backups using the WITH CHECKSUM option.
    • Each backup can be written to either a separate backup file or multiple backup files. However, appending multiple backups (that is, full and t-log) into a single backup media isn't supported.
    • Use compressed backups to reduce the likelihood of experiencing potential issues associated with migrating large backups.
  • Ensure that the service account running the source SQL Server instance has read and write permissions on the SMB network share that contains database backup files.

  • The source SQL Server instance certificate from a database protected by Transparent Data Encryption (TDE) needs to be migrated to the target Azure SQL Managed Instance or SQL Server on Azure virtual machine before you migrate data. To learn more, see Migrate a certificate of a TDE-protected database to Azure SQL Managed Instance and Move a TDE Protected Database to Another SQL Server.

    Tip

    If your database contains sensitive data that is protected by Always Encrypted, the migration process that uses Azure Data Studio with DMS will automatically migrate your Always Encrypted keys to your target Azure SQL Managed Instance or SQL Server on Azure virtual machine.

  • If your database backups are in a network file share, provide a machine to install self-hosted integration runtime to access and migrate database backups. The migration wizard provides the download link and authentication keys to download and install your self-hosted integration runtime. In preparation for the migration, ensure that the machine where you plan to install the self-hosted integration runtime has the following outbound firewall rules and domain names enabled:

    Domain names Outbound ports Description
    Public Cloud: {datafactory}.{region}.datafactory.azure.net
    or *.frontend.clouddatahub.net
    Azure Government: {datafactory}.{region}.datafactory.azure.us
    China: {datafactory}.{region}.datafactory.azure.cn
    443 Required by the self-hosted integration runtime to connect to the Data Migration service.
    For a newly created data factory in the public cloud, locate the FQDN from your self-hosted integration runtime key, which is in format {datafactory}.{region}.datafactory.azure.net. For the old data factory, if you don't see the FQDN in your self-hosted integration key, use *.frontend.clouddatahub.net instead.
    download.microsoft.com 443 Required by the self-hosted integration runtime for downloading the updates. If you have disabled auto-update, you can skip configuring this domain.
    *.core.windows.net 443 Used by the self-hosted integration runtime that connects to the Azure storage account for uploading database backups from your network share

    Tip

    If your database backup files are already provided in an Azure storage account, a self-hosted integration runtime is not required during the migration process.

  • When you're using a self-hosted integration runtime, make sure that the machine where the runtime is installed can connect to the source SQL Server instance and the network file share where backup files are located. Outbound port 445 should be enabled to allow access to the network file share. Also see recommendations for using a self-hosted integration runtime

  • If you're using the Azure Database Migration Service for the first time, ensure that Microsoft.DataMigration resource provider is registered in your subscription. You can follow the steps to register the resource provider

Launch the Migrate to Azure SQL wizard in Azure Data Studio

  1. Open Azure Data Studio and select the server icon to connect to your on-premises SQL Server (or SQL Server on Azure virtual machine).
  2. On the server connection, right-click and select Manage.
  3. On the server's home page, select Azure SQL Migration extension.
  4. On the Azure SQL Migration dashboard, select Migrate to Azure SQL to launch the migration wizard. Launch Migrate to Azure SQL wizard
  5. The first page of the wizard will allow you to start a new session or resume a previously saved one. Pick the first option to start a new session.

Run database assessment, collect performance data and get Azure recommendation

  1. Select the database(s) to run assessment and select Next.
  2. Select Azure SQL Managed Instance as the target. Assessment confirmation
  3. Select on the View/Select button to view details of the assessment results for your database(s), select the database(s) to migrate, and select OK. If any issues are displayed in the assessment results, they need to be remediated before proceeding with the next steps. Database assessment details
  4. Click the Get Azure recommendation button.
  5. Pick the Collect performance data now option and enter a path for performance logs to be collected and click the Start button.
  6. Azure Data Studio will now collect performance data until you either stop the collection, press the Next button in the wizard or close Azure Data Studio.
  7. After 10 minutes you will see a recommended configuration for your Azure SQL Managed Instance. You can also press the Refresh recommendation link after the initial 10 minutes to refresh the recommendation with the additional data collected.
  8. In the above Azure SQL Managed Instance box click the View details button for more information about your recommendation.
  9. Close the view details box and press the Next button.

Configure migration settings

  1. Specify your Azure SQL Managed Instance by selecting your subscription, location, resource group from the corresponding drop-down lists and then select Next.
  2. Select Online migration as the migration mode.

    Note

    In the online migration mode, the source SQL Server database can be used for read and write activity while database backups are continuously restored on target Azure SQL Managed Instance. Application downtime is limited to duration for the cutover at the end of migration.

  3. Select the location of your database backups. Your database backups can either be located on an on-premises network share or in an Azure storage blob container.

    Note

    If your database backups are provided in an on-premises network share, DMS will require you to set up a self-hosted integration runtime in the next step of the wizard. If a self-hosted integration runtime is required to access your source database backups, check the validity of the backup set and upload them to your Azure storage account.
    If your database backups are already on an Azure storage blob container, you don't need to set up a self-hosted integration runtime.

  • For backups located on a network share, provide the following details of your source SQL Server, source backup location, target database name, and Azure storage account for the backup files to be uploaded to:

    Field Description
    Source Credentials - Username The credential (Windows / SQL authentication) to connect to the source SQL Server instance and validate the backup files.
    Source Credentials - Password The credential (Windows / SQL authentication) to connect to the source SQL Server instance and validate the backup files.
    Network share location that contains backups The network share location that contains the full and transaction log backup files. Any invalid files or backups files in the network share that don't belong to the valid backup set will be automatically ignored during the migration process.
    Windows user account with read access to the network share location The Windows credential (username) that has read access to the network share to retrieve the backup files.
    Password The Windows credential (password) that has read access to the network share to retrieve the backup files.
    Target database name The target database name can be modified if you wish to change the database name on the target during the migration process.
    Storage account details The resource group and storage account where backup files will be uploaded to. You do not need to create a container as DMS will automatically create a blob container in the specified storage account during the upload process.
  • For backups stored in an Azure storage blob container specify the below details of the Target database name, Resource group, Azure storage account, Blob container from the corresponding drop-down lists.

    Field Description
    Target database name The target database name can be modified if you wish to change the database name on the target during the migration process.
    Storage account details The resource group, storage account and container where backup files are located.

    Important

    If loopback check functionality is enabled and the source SQL Server and file share are on the same computer, then source won't be able to access the file share using FQDN. To fix this issue, disable loopback check functionality using the instructions here

Create Azure Database Migration Service

  1. Create a new Azure Database Migration Service or reuse an existing Service that you previously created.

    Note

    If you had previously created DMS using the Azure Portal, you cannot reuse it in the migration wizard in Azure Data Studio. Only DMS created previously using Azure Data Studio can be reused.

  2. Select the Resource group where you have an existing DMS or need to create a new one. The Azure Database Migration Service dropdown will list any existing DMS in the selected resource group.
  3. To reuse an existing DMS, select it from the dropdown list and the status of the self-hosted integration runtime will be displayed at the bottom of the page.
  4. To create a new DMS, select Create new. On the Create Azure Database Migration Service, screen provide the name for your DMS and select Create.
  5. After successful creation of DMS, you'll be provided with details to set up integration runtime.
  6. Select on Download and install integration runtime to open the download link in a web browser. Complete the download. Install the integration runtime on a machine that meets the pre-requisites of connecting to source SQL Server and the location containing the source backup.
  7. After the installation is complete, the Microsoft Integration Runtime Configuration Manager will automatically launch to begin the registration process.
  8. Copy and paste one of the authentication keys provided in the wizard screen in Azure Data Studio. If the authentication key is valid, a green check icon is displayed in the Integration Runtime Configuration Manager indicating that you can continue to Register.
  9. After successfully completing the registration of self-hosted integration runtime, close the Microsoft Integration Runtime Configuration Manager and switch back to the migration wizard in Azure Data Studio.
  10. Select Test connection in the Create Azure Database Migration Service screen in Azure Data Studio to validate that the newly created DMS is connected to the newly registered self-hosted integration runtime. Test connection integration runtime
  11. Review the migration summary and select Done to start the database migration.

Monitor your migration

  1. On the Database Migration Status, you can track the migrations in progress, migrations completed, and migrations failed (if any).

    monitor migration dashboard

  2. Select Database migrations in progress to view ongoing migrations and get further details by selecting the database name.

  3. The migration details page displays the backup files and the corresponding status:

    Status Description
    Arrived Backup file arrived in the source backup location and validated
    Uploading Integration runtime is currently uploading the backup file to Azure storage
    Uploaded Backup file is uploaded to Azure storage
    Restoring Azure Database Migration Service is currently restoring the backup file to Azure SQL Managed Instance
    Restored Backup file is successfully restored on Azure SQL Managed Instance
    Canceled Migration process was canceled
    Ignored Backup file was ignored as it doesn't belong to a valid database backup chain

    backup restore details

Complete migration cutover

The final step of the tutorial is to complete the migration cutover to ensure the migrated database in Azure SQL Managed Instance is ready for use. This is the only part in the process that requires downtime for applications that connect to the database and hence the timing of the cutover needs to be carefully planned with business or application stakeholders.

To complete the cutover,

  1. Stop all incoming transactions to the source database and prepare to make any application configuration changes to point to the target database in Azure SQL Managed Instance.
  2. take any tail log backups for the source database in the backup location specified
  3. ensure all database backups have the status Restored in the monitoring details page
  4. select Complete cutover in the monitoring details page

During the cutover process, the migration status changes from in progress to completing. When the cutover process is completed, the migration status changes to succeeded to indicate that the database migration is successful and that the migrated database is ready for use.

Important

After the cutover, availability of SQL Managed Instance with Business Critical service tier only can take significantly longer than General Purpose as three secondary replicas have to be seeded for Always On High Availability group. This operation duration depends on the size of data, for more information, see Management operations duration.

Next steps