We have a requirement to migrate around 800 GB of data from on-premises SQL Server (2012 and 2017) spread across multiple databases to Azure SQL MI. We have run the DMA on the source data and have got some issues (datatype not supported any more, coding style changes etc.). We are planning to use DMS to perform the data migration

My questions are:

  1. Which stage I should perform the remediation, in the source itself before the migration or in the target Azure SQL MI
  2. Which option is preferred for the data migration

1 Answer 1


Data remediation can be done at source and destination based on your application. If it is only about migration and you are moving data from local to cloud, it's better to first migrate and then use the data integration service like Azure Data Factory. The only reason is that when the data source and data transformation services both are on cloud you will get maximum reliability.

Data Migration Service is the commonly used service when moving data local to cloud. You just need to check the compatibility between local SQL Server and the server on cloud.

When you migrate databases to Azure by using Azure Database Migration Service, you can do an offline or an online migration. With an offline migration, application downtime starts when the migration starts. With an online migration, downtime is limited to the time to cut over at the end of migration.

Refer: https://learn.microsoft.com/en-us/azure/dms/tutorial-sql-server-to-managed-instance

  • Thanks for the answer. In this case, we are just migrating the data from local to cloud. But, if we remediate in the target, how can we confirm that all the remediation's are done . Meaning in my source if when I remediate I can run the DMA multiple time to check that all the issues are solved. But, I cannot do that in target, correct? Commented Oct 26, 2021 at 11:54
  • DMS and DMA are two different services both having their own benefits. As you have mentioned you are migrating 800 GB of data, DMA also work fine. I suggest to go through DMS vs DMS. AFAIK, you can perform data remediate on target also. Commented Oct 26, 2021 at 13:11

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.