What is Azure Database Migration Service?
Azure Database Migration Service is a fully managed service designed to enable seamless migrations from multiple database sources to Azure data platforms with minimal downtime (online migrations).
With Azure Database Migration Service currently we offer two versions:
- Database Migration Service - via Azure SQL migration extension for Azure Data Studio, Azure portal, PowerShell and Azure CLI.
- Database Migration Service (classic) - via Azure portal, PowerShell and Azure CLI.
Database Migration Service powers the "Azure SQL Migration" extension for Azure Data Studio, and provides more features. Azure portal, PowerShell and Azure CLI can also be used to access DMS. Currently, it supports SQL Database modernization to Azure. For improved functionality and supportability, consider migrating to Azure SQL Database by using the DMS.
Database Migration Service (classic) via Azure portal, PowerShell and Azure CLI is an older version of the Azure Database Migration Service. It offers database modernization to Azure and support scenarios like – SQL Server, PostgreSQL, MySQL, and MongoDB.
Azure Database Migration Service (classic) - SQL scenarios are on a deprecation path. Since August 1, 2023, you're no longer able to create new Database Migration Service (classic) resources for SQL Server scenarios from Azure portal. The service will be retired on March 15, 2026 for all customers. You can migrate to Azure SQL Database using the latest version of Azure Database Migration Service, which is available as an extension in Azure Data Studio, or by using Azure PowerShell and Azure CLI. For more information, see Retirement notice: Database Migration Service (classic).
Migrate databases with Azure SQL Migration extension for Azure Data Studio
The Azure SQL Migration extension for Azure Data Studio brings together a simplified assessment, recommendation, and migration experience that delivers the following capabilities:
- A responsive user interface that provides you with an end-to-end migration experience that starts with a migration readiness assessment, and SKU recommendation (based on performance data), and finalizes with the actual migration to Azure SQL.
- An enhanced assessment mechanism that can evaluate SQL Server instances, identifying databases that are ready for migration to the different Azure SQL targets.
- An SKU recommendations engine (Preview) that collects performance data from the source SQL Server instance on-premises, generating right-sized SKU recommendations based on your Azure SQL target.
- A reliable Azure service powered by Azure Database Migration Service that orchestrates data movement activities to deliver a seamless migration experience.
- The ability to run online (for migrations requiring minimal downtime) or offline (for migrations where downtime persists through the migration) migration modes to suit your business requirements.
- The flexibility to create and configure a self-hosted integration runtime to provide your own compute for accessing the source SQL Server and backups in your on-premises environment.
- Provides a secure and improved user experience for migrating TDE databases and SQL/Windows logins to Azure SQL.
Check the following step-by-step tutorials for more information about each specific migration scenario by Azure SQL target:
|Migration scenario||Migration mode|
|SQL Server to Azure SQL Managed Instance||Online / Offline|
|SQL Server to SQL Server on Azure Virtual Machine||Online / Offline|
|SQL Server to Azure SQL Database||Offline|
To learn more, see Migrate databases with Azure SQL Migration extension for Azure Data Studio.
Newer version of the Azure Database Migration Service is available as an extension for Azure Data Studio and can be accesses from Azure portal, which improved the functionality, user experience and supportability of the migration service. Consider using the Azure SQL migration extension for Azure Data Studio and DMS Azure portal whenever possible.
The following table compares the functionality of the versions of the Database Migration Service:
|Feature||DMS(classic)||DMS - via Azure SQL extension for ADS||DMS - via Azure portal||Notes|
|Assessment||No||Yes||No||Assess compatibility of the source.|
|SKU recommendation||No||Yes||No||SKU recommendations for the target based on the assessment of the source.|
|Azure SQL Database - Offline migration||Yes||Yes||Yes||Migrate to Azure SQL Database offline.|
|Azure SQL Managed Instance - Online migration||Yes||Yes||Yes||Migrate to Azure SQL Managed Instance online with minimal downtime.|
|Azure SQL Managed Instance - Offline migration||Yes||Yes||Yes||Migrate to Azure SQL Managed Instance offline.|
|SQL Server on Azure SQL VM - Online migration||No||Yes||Yes||Migrate to SQL Server on Azure VMs online with minimal downtime.|
|SQL Server on Azure SQL VM - Offline migration||Yes||Yes||Yes||Migrate to SQL Server on Azure VMs offline.|
|Migrate logins||Yes||Yes||No||Migrate logins from your source to your target.|
|Migrate schemas||Yes||No||Yes||Migrate schemas from your source to your target.|
|Azure portal support||Yes||Partial||Yes||Create and Monitor your migration by using the Azure portal.|
|Integration with Azure Data Studio||No||Yes||No||Migration support integrated with Azure Data Studio.|
|Regional availability||Yes||Yes||Yes||More regions are available with the extension.|
|Improved user experience||No||Yes||Yes||The DMS is faster, more secure, and easier to troubleshoot.|
|Automation||Yes||Yes||Yes||The DMS supports PowerShell and Azure CLI.|
|Private endpoints||No||Yes||Yes||Connect to your source and target using private endpoints.|
|TDE support||No||Yes||No||Migrate databases encrypted with TDE.|
Migrate databases to Azure with familiar tools
Azure Database Migration Service integrates some of the functionality of our existing tools and services. It provides customers with a comprehensive, highly available solution. The service uses the Data Migration Assistant to generate assessment reports that provide recommendations to guide you through the required changes before a migration. It's up to you to perform any remediation required. Azure Database Migration Service performs all the required steps when ready to begin the migration process. Knowing that the process takes advantage of Microsoft's best practices, you can fire and forget your migration projects with peace of mind.
For up-to-date info about the regional availability of Azure Database Migration Service, see Products available by region.