Migrating your on-premise database to Azure can be a daunting task. It requires careful planning and execution to ensure that your data is safely and accurately transferred to the cloud. In this article, we will provide you with a step-by-step guide on how to migrate your on-premise database to Azure.
Step 1: Explore Database Compatibility
Before you begin your database migration to Azure, it is essential to ensure that your current on-premise database is compatible with the Azure database. Compatibility issues may arise when features that exist in an on-prem database, such as linked servers, trace flags, or file streams, are not available in the cloud.
To check for compatibility issues, you can use Microsoft’s Data Migration Assistant. If you encounter any compatibility issues that cannot be resolved, you may need to consider migrating to an SQL Instance on an Azure Virtual Machine or using an Azure Managed Instance.
Step 2: Select the Right Azure Service Model
The overall pricing, service tier, storage, and performance of Azure rely upon the service model you choose. Therefore, choosing the correct service model in the first instance will save you time further down the line. You can deploy the database as either an individual Azure SQL database, within an Elastic Pool, Azure SQL Managed Instance, or within an Azure Virtual Machine.
Step 3: Choose Your Azure Service Tier
Selecting the correct service tier is crucial to achieving optimal performance and managing costs of the Azure database. Opting for a service level that is too high can result in wasted budget, while a service level that is too low will cause reduced function.
To choose the correct service tier, you can use Microsoft’s Azure SQL Database DTU Calculator. This advisory tool is based on CPU, IOPS, and LOG utilization of your existing on-prem database.
Step 4: Identify Your Required Disaster Recovery Level
Azure offers various levels of disaster recovery protection, including high availability and geo-replication across global data centers. The level of disaster recovery you select should be based on your organization’s recovery point objective (RPO) and recovery time objective (RTO). RPO is the acceptable amount of data loss measured in time, while RTO is the maximum acceptable amount of time that your database can be down.
Step 5: Devise a Migration Strategy
Before migrating your on-prem database to Azure, you need to plan your migration strategy carefully. You should consider whether you will use an online or offline strategy, establish whether database downtime is required for the move, and select the migration tool you will use.
There are several migration tools available to help you migrate from on-prem to Azure, including SQL Server Management Studio (SSMS), Database Migration Assistant (DMA), SQL Server Data Tools (SSDT), SQL Package.exe, SQL Azure Migration Wizard, Azure Database Migration Services, and Transactional Replication.
For offline migrations that allow downtime, DMA and SSMS are highly rated tools, while Transaction Replication “pushes” data from the on-prem database to Azure without any downtime.
Step 6: Migrate a Test Database
After migrating a test database, it is important to conduct a thorough testing to ensure that the migration process was successful. This step allows you to identify any issues and resolve them before migrating the live system.
Migration Errors
If any migration errors are reported, you will need to analyze and fix them before the official migration. The migration process should be tested again after the issues are resolved to ensure a successful migration.
Migration Time
The time it takes to migrate the schema and database is an important factor to consider. If the downtime is too long, you may want to consider an online migration. An online migration can minimize downtime by allowing users to continue using the on-premises database while data is being migrated to Azure.
Connection Issues
During the migration of your test copy, it is important to test any external application or user connection issues such as VPN, firewalls, etc. Testing these connections beforehand will help ensure that the migration process does not cause any disruption to your business operations.
Data Readability
After the migration, it is important to ensure that data can be read and written to the Azure database as expected via the application and direct SQL connections or roles. Testing data readability can help identify any issues with data migration and ensure that data is migrated accurately.
Performance Level
Do a test run of some of the actions that you may take on the database, such as running a report and recording the time it takes to assess if the performance level is acceptable. This testing can help identify any performance issues and allow you to optimize the Azure database for optimal performance.
Step 7: Migrate Your Database
Once you have successfully completed all the above steps, you are ready to migrate your database to Azure. It is important to create a migration plan that includes a timeline and identifies key milestones to ensure a successful migration. Here are some tips to keep in mind when migrating your database:
- Ensure that all necessary data has been migrated to Azure.
- Verify that all applications are correctly connected to the Azure database.
- Test the performance of the Azure database to ensure it meets your requirements.
- Monitor the Azure database to ensure that it is functioning correctly after the migration.
- Establish a disaster recovery plan to ensure that your data is protected in the event of a disaster.
By following these steps, you can ensure a smooth and successful migration of your on-premises database to Azure. Migrating to Azure can bring a host of benefits, including increased scalability, flexibility, and cost savings, making it a worthwhile investment for businesses looking to optimize their data management systems.