Data Migration Assistant: Best Practices

Follow these best practices to run Data Migration Assistant:


  • Do not install and execute Data Migration Assistance (DMA) directly on SQL Server host machine.


  • Run assessments on production databases during non-peak times.
  • Perform the “Compatibility issues” and “New feature recommendations” assessments separately to reduce the assessment duration.


  • Migrate a server during non-peak times.
  • When migrating a database, provide a single share location accessible by source server and target server, and avoid copy operation if possible. Based on the size of the backup file, copy operation will introduce delay. It also increases the chances of failing migration due to an extra step. If a single location is provided then DMA will bypass copy operation. However, please make sure that the correct permissions are given to the the shared folder to avoid migration failures. The correct permissions are specified in the tool. If SQL Server instance runs under Network Service credentials, then give the machine account of the instance the correct permissions on the shared folder.
  • Enable "encrypt connection" when connecting to Source and Target server. Using SSL encryption increases the security of data transmitted across the networks between DMA and the SQL Server instance. This is beneficial esp when migrating SQL Logins. If SSL encryption is not used and the network is compromised by an attacker, then the SQL Logins being migrated could get intercepted and/or modified, on-the-fly by the attacker. However, if all access involves a secure intranet configuration, encryption might not be required. Enabling encryption does slow performance due to extra overhead to encrypt and decrypt packets. For more information please refer to Encrypting Connections to SQL Server
Comments (4)

  1. Ju Bilker says:

    I have run DMA v3.1 on SQL Server 2014, no customize database other than default system database. The process was running over a night, no report generated.

    So the 2nd morning, I killed the process, follow instruction here and restart to assess other server. Unfortunately, no report was generated as well.

    Please advise normally whether it happens to others as well. Thanks.

    1. Harini Gupta says:

      Hi Ju, I am sorry to hear about the issues you are having with DMA assessments. Can you share DMA logs? Logs can be located here:

  2. Anurag Mishra says:

    Hi Harini,

    The general best practice suggests that ,
    Do not install and execute Data Migration Assistance (DMA) directly on SQL Server host machine.

    Then suppose i need to do an assessment and migration for a client Database , then what should be the approach w.r.t environments ?

    Scenario – need to upgrade from SQL server 2008/12/14 to sql server 2016.

    what all backup needs to be taken ?

  3. Tracy M says:

    How can this tool be used to migrate a production database base without losing the transactions made in the source database while it is restoring? The production database takes 8 hours to restore, taking it offline to prevent changes in the source is not an option. Is there anyway to specify restore options so that log Shipping can be used?

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