Edit

Tutorial: Migrate SQL Server to SQL Server on Azure Virtual Machines offline in Azure Data Studio

  • Article
  • 15 minutes to read

You can use Azure Database Migration Service and the Azure SQL Migration extension in Azure Data Studio to migrate databases from an on-premises instance of SQL Server to SQL Server on Azure Virtual Machines (SQL Server 2016 and later) offline and with minimal downtime.

For database migration methods that might require some manual configuration, see SQL Server instance migration to SQL Server on Azure Virtual Machines.

In this tutorial, learn how to migrate the example AdventureWorks database from an on-premises instance of SQL Server to an instance of SQL Server on Azure Virtual Machines by using Azure Data Studio and Azure Database Migration Service. This tutorial uses offline migration mode, which considers an acceptable downtime during the migration process.

In this tutorial, you learn how to:

  • Open the Migrate to Azure SQL wizard in Azure Data Studio
  • Run an assessment of your source SQL Server databases
  • Collect performance data from your source SQL Server instance
  • Get a recommendation of the SQL Server on Azure Virtual Machines SKU that will work best for your workload
  • Set the details of your source SQL Server instance, backup location, and target instance of SQL Server on Azure Virtual Machines
  • Create an instance of Azure Database Migration Service
  • Start your migration and monitor progress to completion

This tutorial describes an offline migration from SQL Server to SQL Server on Azure Virtual Machines. For an online migration, see Migrate SQL Server to SQL Server on Azure Virtual Machines online in Azure Data Studio.

Prerequisites

Before you begin the tutorial:

  • Download and install Azure Data Studio.

  • Install the Azure SQL Migration extension from Azure Data Studio Marketplace.

  • Have an Azure account that's assigned to one of the following built-in roles:

    • Contributor for the target instance of SQL Server on Azure Virtual Machines and for the storage account where you upload your database backup files from a Server Message Block (SMB) network share
    • Reader role for the Azure resource group that contains the target instance of SQL Server on Azure Virtual Machines or for your Azure Storage account
    • Owner or Contributor role for the Azure subscription

    As an alternative to using one of these built-in roles, you can assign a custom role.

    Important

    An Azure account is required only when you configure the migration steps. An Azure account isn't required for the assessment or to view Azure recommendations in the migration wizard in Azure Data Studio.

  • Create a target instance of SQL Server on Azure Virtual Machines.

    Important

    If you have an existing Azure virtual machine, it should be registered with the SQL IaaS Agent extension in Full management mode.

  • Ensure that the logins that you use to connect the source SQL Server instance are members of the SYSADMIN server role or have CONTROL SERVER permission.

  • Provide an SMB network share, Azure storage account file share, or Azure storage account blob container that contains your full database backup files and subsequent transaction log backup files. Database Migration Service uses the backup location during database migration.

    Important

    • The Azure SQL Migration extension for Azure Data Studio doesn't take database backups, or neither initiate any database backups on your behalf. Instead, the service uses existing database backup files for the migration.
    • If your database backup files are in an SMB network share, create an Azure storage account that Database Migration Service can use to upload database backup files to and to migrate databases. Make sure you create the Azure storage account in the same region where you create your instance of Database Migration Service.
    • You can write each backup to either a separate backup file or to multiple backup files. Appending multiple backups such as full and transaction logs into a single backup media isn't supported.
    • You can provide compressed backups to reduce the likelihood of experiencing potential issues associated with migrating large backups.

  • Ensure that the service account that's running the source SQL Server instance has read and write permissions on the SMB network share that contains database backup files.

  • If you're migrating a database that's protected by Transparent Data Encryption (TDE), the certificate from the source SQL Server instance must be migrated to SQL Server on Azure Virtual Machines before you migrate data. To learn more, see Move a TDE-protected database to another SQL Server instance.

    Tip

    If your database contains sensitive data that's protected by Always Encrypted, the migration process automatically migrates your Always Encrypted keys to your target instance of SQL Server on Azure Virtual Machines.

  • If your database backups are on a network file share, provide a computer on which you can install a self-hosted integration runtime to access and migrate database backups. The migration wizard gives you the download link and authentication keys to download and install your self-hosted integration runtime.

    In preparation for the migration, ensure that the computer on which you install the self-hosted integration runtime has the following outbound firewall rules and domain names enabled:

    Domain names Outbound port Description
    Public cloud: {datafactory}.{region}.datafactory.azure.net
    or *.frontend.clouddatahub.net

    Azure Government: {datafactory}.{region}.datafactory.azure.us

    Azure China: {datafactory}.{region}.datafactory.azure.cn    		 443 Required by the self-hosted integration runtime to connect to Database Migration Service.

    For a newly created data factory in a public cloud, locate the fully qualified domain name (FQDN) from your self-hosted integration runtime key, in the format {datafactory}.{region}.datafactory.azure.net.

    For an existing 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 to upload 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 isn't required during the migration process.

  • If you use a self-hosted integration runtime, make sure that the computer on which the runtime is installed can connect to the source SQL Server instance and the network file share where backup files are located.

  • Enable outbound port 445 to allow access to the network file share. For more information, see recommendations for using a self-hosted integration runtime.

  • If you're using Azure Database Migration Service for the first time, make sure that the Microsoft.DataMigration resource provider is registered in your subscription.

Open the Migrate to Azure SQL wizard in Azure Data Studio

To open the Migrate to Azure SQL wizard:

  1. In Azure Data Studio, go to Connections. Select and connect to your on-premises instance of SQL Server. You also can connect to SQL Server on an Azure virtual machine.

  2. Right-click the server connection and select Manage.

  3. In the server menu under General, select Azure SQL Migration.

  4. In the Azure SQL Migration dashboard, select Migrate to Azure SQL to open the migration wizard.

    Screenshot that shows how to open the Migrate to Azure SQL wizard.

  5. On the first page of the wizard, start a new session or resume a previously saved session.

Run a database assessment, collect performance data, and get Azure recommendations

  1. In Step 1: Databases for assessment in the Migrate to Azure SQL wizard, select the databases you want to assess. Then, select Next.

  2. In Step 2: Assessment results and recommendations, complete the following steps:

    1. In Choose your Azure SQL target, select SQL Server on Azure Virtual Machine.

      Screenshot that shows an assessment confirmation.

    2. Select View/Select to view the assessment results.

    3. In the assessment results, select the database, and then review the assessment report to make sure no issues were found.

    4. Select Get Azure recommendation to open the recommendations pane.

    5. Select Collect performance data now. Select a folder on your local computer to store the performance logs, and then select Start.

      Azure Data Studio collects performance data until you either stop data collection or you close Azure Data Studio.

      After 10 minutes, Azure Data Studio indicates that a recommendation is available for SQL Server on Azure Virtual Machines. After the first recommendation is generated, you can select Restart data collection to continue the data collection process and refine the SKU recommendation. An extended assessment is especially helpful if your usage patterns vary over time.

    6. In the selected SQL Server on Azure Virtual Machines target, select View details to open the detailed SKU recommendation report:

    7. In Review SQL Server on Azure Virtual Machines Recommendations, review the recommendation. To save a copy of the recommendation, select the Save recommendation report checkbox.

  3. Select Close to close the recommendations pane.

  4. Select Next to continue your database migration in the wizard.

Configure migration settings

  1. In Step 3: Azure SQL target in the Migrate to Azure SQL wizard, select your Azure account, Azure subscription, the Azure region or location, and the resource group that contains the target SQL Server to Azure Virtual Machines instance. Then, select Next.

  2. In Step 4: Migration mode, select Offline migration, and then select Next.

    Note

    In offline migration mode, the source SQL Server database shouldn't be used for write activity while database backup files are restored on the target instance of SQL Server to Azure Virtual Machines. Application downtime persists from the start of the migration process until it's finished.

  3. In Step 5: Data source configuration, select the location of your database backups. Your database backups can be located either 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, you must set up a self-hosted integration runtime in the next step of the wizard. A self-hosted integration runtime is required to access your source database backups, check the validity of the backup set, and upload backups to Azure storage account.

    If your database backups are already in an Azure storage blob container, you don't need to set up a self-hosted integration runtime.

    For backups that are located on a network share, enter or select the following information:

    Name Description
    Source Credentials - Username The credential (Windows and SQL authentication) to connect to the source SQL Server instance and validate the backup files.
    Source Credentials - Password The credential (Windows and 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 backup files in the network share that don't belong to the valid backup set are 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 You can modify the target database name during the migration process.

    For backups that are stored in an Azure storage blob container, enter or select the following information:

    Name Description
    Target database name You can modify the target database name during the migration process.
    Storage account details The resource group, storage account, and container where backup files are located.
    Last Backup File The file name of the last backup of the database you're migrating.

    Important

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

Create a Database Migration Service instance

In Step 6: Azure Database Migration Service in the Migrate to Azure SQL wizard, create a new instance of Azure Database Migration Service or reuse an existing instance that you created earlier.

Note

If you previously created a Database Migration Service instance by using the Azure portal, you can't reuse the instance in the migration wizard in Azure Data Studio. You can reuse an instance only if you created the instance by using Azure Data Studio.

Use an existing instance of Database Migration Service

To use an existing instance of Database Migration Service:

  1. In Resource group, select the resource group that contains an existing instance of Database Migration Service.

  2. In Azure Database Migration Service, select an existing instance of Database Migration Service that's in the selected resource group.

  3. Select Next.

Create a new instance of Database Migration Service

To create a new instance of Database Migration Service:

  1. In Resource group, create a new resource group to contain a new instance of Database Migration Service.

  2. Under Azure Database Migration Service, select Create new.

  3. In Create Azure Database Migration Service, enter a name for your Database Migration Service instance, and then select Create.

  4. Under Set up integration runtime, complete the following steps:

    1. Select the Download and install integration runtime link to open the download link in a web browser. Download the integration runtime, and then install it on a computer that meets the prerequisites to connect to the source SQL Server instance.

      When installation is finished, Microsoft Integration Runtime Configuration Manager automatically opens to begin the registration process.

    2. In the Authentication key table, copy one of the authentication keys that are provided in the wizard and paste it in Azure Data Studio. If the authentication key is valid, a green check icon appears in Integration Runtime Configuration Manager. A green check indicates that you can continue to Register.

      After you register the self-hosted integration runtime, close Microsoft Integration Runtime Configuration Manager.

      Note

      For more information about how to use the self-hosted integration runtime, see Create and configure a self-hosted integration runtime.

  5. In Create Azure Database Migration Service in Azure Data Studio, select Test connection to validate that the newly created Database Migration Service instance is connected to the newly registered self-hosted integration runtime.

  6. Return to the migration wizard in Azure Data Studio.

Start the database migration

In Step 7: Summary in the Migrate to Azure SQL wizard, review the configuration you created, and then select Start migration to start the database migration.

Monitor the database migration

  1. In Azure Data Studio, in the server menu under General, select Azure SQL Migration to go to the dashboard for your Azure SQL migrations.

    Under Database migration status, you can track migrations that are in progress, completed, and failed (if any), or you can view all database migrations.

    monitor migration dashboard

  2. Select Database migrations in progress to view active migrations.

    To get more information about a specific migration, select the database name.

    The migration details pane displays the backup files and their corresponding status:

    Status Description
    Arrived The backup file arrived in the source backup location and was validated.
    Uploading The integration runtime is uploading the backup file to Azure storage.
    Uploaded The backup file has been uploaded to Azure storage.
    Restoring The service is restoring the backup file to SQL Server on Azure Virtual Machines.
    Restored The backup file was successfully restored on SQL Server on Azure Virtual Machines.
    Canceled The migration process was canceled.
    Ignored The backup file was ignored because it doesn't belong to a valid database backup chain.

After all database backups are restored on the instance of SQL Server on Azure Virtual Machines, an automatic migration cutover is initiated by Database Migration Service to ensure that the migrated database is ready to use. The migration status changes from In progress to Succeeded.

Limitations

Migrating to SQL Server on Azure VMs by using the Azure SQL extension for Azure Data Studio has the following limitations:

  • If migrating a single database, the database backups must be placed in a flat-file structure inside a database folder (including container root folder), and the folders can't be nested, as it's not supported.
  • If migrating multiple databases using the same Azure Blob Storage container, you must place backup files for different databases in separate folders inside the container.
  • Overwriting existing databases using DMS in your target SQL Server on Azure Virtual Machine isn't supported.
  • Configuring high availability and disaster recovery on your target to match source topology isn't supported by DMS.
  • The following server objects aren't supported:
    • SQL Server Agent jobs
    • Credentials
    • SSIS packages
    • Server audit
  • You can't use an existing self-hosted integration runtime created from Azure Data Factory for database migrations with DMS. Initially, the self-hosted integration runtime should be created using the Azure SQL migration extension in Azure Data Studio and can be reused for further database migrations.
  • VM with SQL Server 2008 and below as target versions aren't supported when migrating to SQL Server on Azure Virtual Machines.
  • If you're using a VM with SQL Server 2012 or SQL Server 2014, you need to store your source database backup files on an Azure Storage Blob Container instead of using the network share option. Store the backup files as page blobs since block blobs are only supported in SQL 2016 and after.
  • You must make sure the SQL IaaS Agent Extension in the target Azure Virtual Machine is in Full mode instead of Lightweight mode.
  • SQL IaaS Agent Extension only supports management of Default Server Instance or Single Named Instance,
  • There is a temporary limit of 80 databases per target Azure Virtual Machine. A workaround to break the limit (reset the counter) is to Uninstall and Reinstall SQL IaaS Agent Extension in the target Azure Virtual Machine.
  • Apart from configuring the Networking/Firewall of your Azure Storage Account to allow your VM to access backup files. You also need to configure the Networking/Firewall of your SQL Server on Azure VM to allow outbound connection to your storage account.
  • You need to keep the target SQL Server on Azure VM power ON while the SQL Migration is in progress. Also, when creating a new migration, failover or cancel the migration.
  • Error: Login failed for user 'NT Service\SQLIaaSExtensionQuery. Reason: SQL Server instance is in single-user mode. One possible reason is the target SQL Server on Azure VM is in upgrade mode. Solution: Please wait for the target SQL Server on Azure VM exit the upgrade mode and start migration again.
  • Error: Ext_RestoreSettingsError, message: Failed to create restore job.;Cannot create file 'F:\data\XXX.mdf' because it already exists. Solution: Connect to the target SQL Server on Azure VM and delete the XXX.mdf file. Then, start migration again.

Next steps