Azure Database Migration Service hybrid mode now in preview

[Venkata Raj Pochiraju]

We are pleased to announce preview of Microsoft Azure Database Migration Service hybrid mode, which manages migration using a migration worker hosted on-premises along with an instance of Azure Database Migration Service running in the cloud (the “cloud service”) to manage database migrations. Azure Database Migration Service hybrid mode is especially useful for scenarios in which there is a lack of site-to-site connectivity between the on-premises network and Azure or if there is limited site-to-site connectivity bandwidth.

Use Azure Database Migration Service hybrid mode if your network security policies prevent Network Security Group (NSG) rules allowing inbound traffic for the cloud instance of Azure Database Migration Service.

You can use Azure Database Migration Service in hybrid mode to migrate on-premises databases to Azure in five simple steps:

1. Create an instance of Azure Database Migration Service in hybrid mode.
2. Download, install, and set up the Azure Database Migration Service hybrid worker in your on-premises network.
3. Create a migration project and start online migration using the hybrid mode instance of Azure Database Migration Service set up in the first step.
4. Monitor migration.
5. Perform the cutover when you are ready.

Currently, Azure Database Migration Service running in hybrid mode supports SQL Server migrations to:

• Azure SQL Database managed instance with near zero downtime (online).
• Azure SQL Database single database with some downtime (offline).

We will add support for additional migration scenarios in future releases.

For additional information about this new functionality, see the tutorial Get started with Azure Database Migration Service -hybrid mode and perform friction free migrations.

DMS_Hybrid_Script.zip

[thommck]

I've been trying to get more info on this to understand the difference between a normal DMS approach compared to a Hybrid DMS.

How does it help with the reasons you describe (e.g. low latency/bandwidth) and what does the hybrid worker actually do on behalf of the cloud service?

I can't see why a Security team would block firewall rules for connecting to the DMS Cloud Service but allow them to connect to an Azure SQL DB (or any other cloud resource in my tenant!)?

[Venkata Raj Pochiraju]

Hello,

The Cloud version of DMS service is fully managed by Microsoft.  Where as with Hybrid DMS, you need to have a server that can host the Hybrid DMS worker in the on-premises network.  In the case of Hybrid- DMS, you still need to create DMS service in the cloud, but the cloud DMS will only be used for managing, orchestrating and status monitoring your migration pipelines.  The actual migration tasks are executed by Hybrid worker that includes the backup file validation, upload to to Blob storage , calling the restore onto the target MI and final cutover.

With Cloud DMS, you need to have a site-site connectivity (ExpressRoute or VPN) between your on-prem and Azure networks, but with Hybrid DMS, you don't have to, the file uploads happen through the public internet.  You don't have to worry about opening SQL Server port and SMB ports at Azure NSG.  Hope this helps.  Please let us know if you need more info.

[thommck]

Thats much clearer thanks, it would be good to add that info on the Microsoft Docs page for it.

[Laurismad]

Hi, this type of migration can be secured?

[dirceuresende]

I'm trying to download the installer for Hybrid Azure Database Migration Service on both Edge and Chrome, and none are able to download the file. I'm stuck on the "Downloading the file... Please do not close this blade." screen..