AZ-305 Question 215
Select 2Your organization needs to migrate five on-premises SQL Server databases (each around 500 GB) to Azure SQL Database with minimal downtime. The business requires that database modifications continue on-premises until just before the cutover. Which two migration methods best meet these requirements? (Choose two.)
- A
Use Azure Database Migration Service (DMS) with an offline migration approach.
- B
Use Azure Database Migration Service (DMS) with an online migration approach.
- C
Export BACPAC files from on-premises SQL Server and import them into Azure SQL Database.
- D
Configure transactional replication from on-premises SQL Server to Azure SQL Database.
- E
Take a manual backup of on-premises SQL Server and restore it in Azure using Azure Backup.
Show answer and explanation
Correct answers: B, D
Explanation
To achieve minimal downtime and continuous data synchronization, an online migration approach is required. Azure Database Migration Service (DMS) in online mode and SQL transactional replication both allow data to remain synchronized with the source until just before final cutover, meeting the requirement for minimal service disruption. For more information, see Microsoft’s official documentation on Azure Database Migration Service at https://learn.microsoft.com/azure/dms/ and Transactional Replication at https://learn.microsoft.com/sql/relational-databases/replication/transactional/transactional-replication.
- A. Incorrect.
Option 1: Use Azure Database Migration Service (DMS) with an offline migration approach. - INCORRECT. Although DMS can handle the data movement, offline migration does not continuously synchronize data during the process, resulting in longer downtime. This does not meet the requirement for minimal downtime and continuous sync before cutover.
- B. Correct.
Option 2: Use Azure Database Migration Service (DMS) with an online migration approach. - CORRECT. Online (or continuous) migration keeps the target in sync with the source until cutover, minimizing downtime. DMS online mode uses an initial copy followed by incremental data sync, allowing near-zero downtime.
- C. Incorrect.
Option 3: Export BACPAC files from on-premises SQL Server and import them into Azure SQL Database. - INCORRECT. This is typically a fully offline operation. The on-premises databases must be taken offline or locked for the export, and no continuous sync occurs. Downtime can be significant for large databases.
- D. Correct.
Option 4: Configure transactional replication from on-premises SQL Server to Azure SQL Database. - CORRECT. Transactional replication can keep the data in sync by replicating changes as they occur, allowing near-zero downtime before final cutover. This meets the requirement for continuous data synchronization.
- E. Incorrect.
Option 5: Take a manual backup of on-premises SQL Server and restore it in Azure using Azure Backup. - INCORRECT. While backups can migrate the data, they do not provide a mechanism for near-real-time replication. This would incur downtime during backup, transfer, and restore, and does not continuously synchronize updated data.