Using Azure Dms is it possible to migarte sql databse of 5Tb to azure Vm with ? What are limitations and known issues while migrating huge dbs to azure vm with azure DMS tool?

Question

We are planning to migrate 5 Tb of sql db to azure Vm with help of azure DMS ? does dms support sql db with huge sizes like this?

Azure Dms does supports only offline migration for azure vm .

what is avg time taken by for migrating sql db
with 100 gb size ?

Does any other factors create an issue while we migration of huge dbs ?

Answer 1

Hi @Vishnuvardhan Settipally ,

> does dms support sql db with huge sizes like this?

Yes, it is supported. According to MS document, Azure DMS is recommended for large (in terms of number and size of databases) migrations – DMS can migrate databases at scale.

> Does any other factors create an issue while we migration of huge dbs ?

Suggest you check if your environment meet the requirements of using Azure DMS.

Azure Database Migration Service prerequisites that are common across all supported migration scenarios include the need to:

•Create a Microsoft Azure Virtual Network for Azure Database Migration Service by using the Azure Resource Manager deployment model, which provides site-to-site connectivity to your on-premises source servers by using either ExpressRoute or VPN.

•Ensure that your virtual network Network Security Group rules don't block the following communication ports 443, 53, 5671-5672, 9350-9354, 445, 12000. For more detail on virtual network NSG traffic filtering, see the article Filter network traffic with network security groups.

•When using a firewall appliance in front of your source database(s), you may need to add firewall rules to allow Azure Database Migration Service to access the source database(s) for migration.

Please refer to this MS document to get more information.

Best regards,
Cathy

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Answer 2

Hi @Vishnuvardhan Settipally ,

Sorry for reply late.

> what is average migration time for 500 gb of db with Dms?

It depends on your environment. Some factors will effect this. According to MS document,

Are there any recommendations for optimizing the performance of Azure Database Migration Service? You can do a few things to speed up your database migration using the service:

•Use the multi CPU General Purpose Pricing Tier when you create your service instance to allow the service to take advantage of multiple vCPUs for parallelization and faster data transfer.
•Temporarily scale up your Azure SQL Database target instance to the Premium tier SKU during the data migration operation to minimize Azure SQL Database throttling that may impact data transfer activities when using lower-level SKUs.

Hope this could help you.

> does Dms resumes migration or does it restart migration ?

I do not have Azure environment to test this for you. I could not give you a confirm answer.

Best regards,
Cathy

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