AZ-305 Question 213
Single answerYour company needs to migrate a 500 GB on-premises SQL Server database to Azure SQL Database with minimal downtime. The database is mission-critical and must remain available as much as possible during the migration. Which approach should you recommend to best achieve this requirement?
- A
Export the on-premises database to a BACPAC file and import it into Azure SQL Database
- B
Use Azure Database Migration Service (DMS) in an online migration scenario
- C
Manually copy the MDF and LDF files to Azure Blob Storage and attach them to Azure SQL Database
- D
Configure regular SQL Server log shipping from on-premises to Azure SQL Database
Show answer and explanation
Correct answer: B
Explanation
Azure Database Migration Service in an online migration scenario is specifically designed to keep downtime minimal by replicating changes continuously and performing a final cutover when ready. Other methods like BACPAC imports or attaching data files either require significant downtime or are not supported for Azure SQL Database. For more details, see the Azure Database Migration Service documentation: https://learn.microsoft.com/azure/database-migration/
- A. Incorrect.
Although exporting and importing with a BACPAC file is a valid approach, it generally requires taking the database offline or operating in a read-only mode for a longer period. This method can lead to more downtime, making it less ideal for a minimal downtime requirement.
- B. Correct.
Using Azure Database Migration Service (DMS) in an online migration scenario allows data to be continuously replicated to Azure SQL Database while the source remains operational. This approach reduces downtime to a brief final cutover window, making it a strong choice for mission-critical databases.
- C. Incorrect.
Azure SQL Database does not support directly attaching on-premises MDF and LDF files, so this method is not a valid migration approach. Data at rest must be imported or migrated through supported tools (e.g., DMS, BACPAC).
- D. Incorrect.
Log shipping is not supported when migrating directly to Azure SQL Database. This technique works for specific configurations in IaaS-based SQL Server scenarios, but not with Platform as a Service (PaaS) solutions like Azure SQL Database.