Migration to Azure SQL is a structured process involving preliminary assessments, migration itself, and post-migration activities. This process targets databases like SQL Server, MongoDB, MySQL, Cassandra, and other operational databases.
Requirements for migration can be grouped into four categories:
- Source Environment
- Target Environment
- Security
- Performance
Source Environment
The source environment makes up the infrastructure from which your data is moving. You need a precise inspection of the existing databases, including types, versions, sizes, and locations to pull this off. Compatibility issues should be identified and resolved beforehand to prevent failure during the migration process.
Example:
In the case of SQL Server to Azure SQL Database managed instances, the source and target versions of SQL Server must be compatible. For instance, the source version of SQL Server must be either 2005 or higher.
Target Environment
The aim of any migration process is to ensure an efficient and seamless operation in the new environment. Therefore, understanding the characteristics and components of your target environment is paramount. These include services like Azure SQL Database, Azure SQL Managed Instance, SQL Server on Azure Virtual Machines, among others.
Also, consider the target region, storage type, and compute size when planning for the migration.
Security
The primary objective is to ensure data protection while complying with security requirements in the new system.
For Example:
Transform sensitive data through masking or redaction before migration. Additionally, employ Azure’s built-in features for data protection such as Azure Active Directory for Identity and Access Management, Azure Key Vault for encryption keys and secrets, Azure Private Link for private access to Azure Services, etc.
Performance
Understanding performance requirements is crucial. Some parameters to consider include:
- Disk speed – Provisioned IOPS, MBps
- Cores – Virtual CPU numbers
- Memory – Capacity of RAM
- Max data size
These play a crucial role in deciding the correct pricing tier and hardware setup to meet your performance needs.
Tools like Database Experimentation Assistant (DEA) or Database Migration Assistant (DMA) can be used to evaluate performance-related issues in your source and target environments.
Other Considerations
You should also consider other factors like network connectivity, downtime tolerance, and operational contingencies during the migration process.
After understanding these requirements you can choose from several migration strategies available such as offline (one-time) migration, online (continuous) migration, or a hybrid approach depending on your business needs.
Remember, the success of a database migration to Microsoft Azure SQL solutions is dependent on a meticulous evaluation of each encapsulated requirement. As mentioned earlier, these make up an integral part of the DP-300 Administering Microsoft Azure SQL Solutions exam and must be comprehended thoroughly.
Practice Test
True or False: Understanding the workload of your database is not a key part of evaluating requirements for migration.
- True
- False
Answer: False.
Explanation: Understanding the workload of your database including its peak usage, growth potential, and performance is vital when evaluating migration requirements. It helps to determine the necessary resources for Azure SQL.
Which Azure tool would you use to evaluate your on-premises database for migration to Azure?
- A. Azure Advisor
- B. Azure Migrate
- C. Azure Monitor
- D. Azure Security Center
Answer: B. Azure Migrate
Explanation: Azure Migrate is a Microsoft tool that provides guidance, insights, and mechanisms to assist you in migrating to Azure. It helps assess on-premises workloads for migration.
Multiple Select: Which are the key components to evaluate when planning the migration of SQL Server databases to Azure?
- A. Server specification
- B. Database size
- C. Data workload
- D. Programming language of the application
Answer: A. Server specification, B. Database size, C. Data workload.
Explanation: The server specification, database size, and data workload are key components to consider when planning a migration. The Programming language of the application is not directly related to the data migration process.
True or False: Compatibility issues with Azure SQL are not a consideration when evaluating requirements for migration.
- True
- False
Answer: False.
Explanation: Compatibility issues should be at the core of any migration consideration. Some features available in SQL Server might not be supported in Azure SQL and might require adjustment before migration.
What does the Data Migration Assistant tool do within the Azure environment?
- A. It transfers data from your local server to Azure.
- B. It helps with the query performance insights.
- C. It assesses on-premises SQL Server instance for migrating to Azure SQL database.
- D. It configures firewall rules for the new database server.
Answer: C. It assesses on-premises SQL Server instance for migrating to Azure SQL database.
Explanation: Data Migration Assistant (DMA) enables you to upgrade to a modern data platform by detecting compatibility issues that can impact database functionality in your new version of SQL Server or Azure SQL Database.
True or False: You do not need to establish connectivity and name resolution before migrating your database to Azure.
- True
- False
Answer: False.
Explanation: Before initiating database migration to Azure, establishing connectivity and name resolution is essential to maintain smooth communication between the on-premises network and the Azure vNet respectively.
When migrating databases, should you put your focus on the moving part or stationary part of the data?
- A. Moving part
- B. Stationary part
- C. Both
- D. None
Answer: C. Both
Explanation: In migration strategy, both moving and stationary parts of the data need attention. Moving data needs to be transferred efficiently and stationary data needs to be correctly provisioned in the target environment.
True or False: The existing SQL Server version and compatibility level does not impact the migration process.
- True
- False
Answer: False.
Explanation: The existing SQL Server version and its compatibility level is an integral part to be considered during migration, as some features might not be supported in Azure SQL or might need adjustment.
If you decide to perform an offline migration to minimize downtime, does it mean you’ll need more time for migration?
- A. True
- B. False
Answer: A. True
Explanation: In an offline migration data is copied while the source database is detached from the application, causing downtime and hence the migration process needs to be completed as quickly as possible which requires more resources and planning.
Multiple Select: Which type of applications would be the best fit for Azure SQL Database?
- A. Cloud-native applications
- B. On-premise applications
- C. Modern applications
- D. Legacy applications
Answer: A. Cloud-native applications, C. Modern applications.
Explanation: Azure SQL Database is built for cloud-native and modern applications which can take full advantage of scalability, high availability, and other cloud features. On-premise and legacy applications may require extensive modification before they are suitable for Azure SQL Database.
Interview Questions
What is the primary advantage of migrating on-premises SQL Server databases to Azure SQL Database?
The primary advantage is the ability to replace on-premises hardware with a cloud-based solution, allowing organizations to save on hardware and maintenance costs.
What is Azure Database Migration Service (DMS)?
Azure Database Migration Service (DMS) is a tool from Microsoft Azure that helps you simplify, guide, and automate your database migration to Azure.
What would you need to evaluate before initiating the migration process to Azure SQL?
Before initiating the migration, one would need to evaluate the compatibility level of the current SQL Server, database size, security requirements, application dependencies, performance capabilities and expected recovery time in case of failures.
What is the role of the Data Migration Assistant (DMA) in Azure SQL migrations?
The Data Migration Assistant (DMA) helps you upgrade your SQL Server instance to Azure SQL Database by detecting compatibility issues that might affect functionality in the target environment.
Can Azure Database Migration Service (DMS) perform online migrations?
Yes, Azure DMS can perform online migrations with minimal downtime. It keeps your source database synchronized with the target database until you are ready to complete the migration.
Why do we need to evaluate throughput for Azure SQL Database until completion of migration?
It is crucial to ensure that the migration process does not congest the network resources needed for normal business operations. Evaluating throughput helps manage resource usage and maintain optimal performance during the migration.
What is the purpose of the ‘Assess’ phase in Azure Database Migration Guide?
The ‘Assess’ phase in Azure Database Migration Guide helps identify the potential issues that might occur during the migration. This includes understanding the features currently in use, difficulties faced in migration, and handling potential roadblocks.
Why should we validate databases after migrating them to Azure SQL Database?
Database validation after migration is necessary to ensure all data has been transferred correctly and the database functions as expected in the new environment. It helps in maintaining data integrity and operational continuity.
Should we consider application compatibility when planning for Azure SQL migration?
Yes, application compatibility is a crucial factor since the application needs to operate correctly with the database after migration. It is necessary to understand the dependencies and if any changes are required in the application to work seamlessly with the Azure SQL Database.
Can staging databases be used as part of the migration process to Azure SQL Database?
Yes, staging databases can be used as part of the migration process. This approach is useful when you need to perform transformations or cleansing on the data before it is migrated to the final Azure SQL Database.
What important aspect should be considered regarding transaction log files during migration?
It’s essential to monitor the size and growth of transaction log files during the migration. Oversized transaction logs might cause issues as they can fill up all available disk space affecting database performance and availability.
Why is downtime management significant for tasks like Azure SQL Database migration?
Downtime management is crucial for business continuity. While migrating, downtime should be minimized to prevent interruptions in user access to applications and databases.
Should database backups be considered as part of the migration strategy?
Yes, having a backup of databases is an absolute necessity prior to migration. This offers a safety net if there is a need to roll back to the original state because of an error or data corruption during migration.
What could be a significant indicator to consider vertical scaling in Azure SQL Database migration?
The need for vertical scaling might be indicated when the database operations require more compute power, memory, storage or improved processing capabilities beyond what the current configuration can support.
Should I monitor the performance of my database after migration to Azure SQL Database?
Yes, monitoring the performance after migration is critical to assess the efficiency of the new environment, identify potential issues, ensure that the database is performing optimally, and make necessary adjustments.
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