Migration between Azure SQL services can be a fairly tedious and comprehensive process if not carried out systematically.
Aspiring Microsoft Azure SQL administrators appearing for the DP-300 exam would need to fully comprehend this process, given its ubiquity in professional settings. The process of migrating databases to Azure SQL involves phases such as planning, assessing compatibility, running the Data Migration Assistant tool, among other steps.
Understanding Migration to Azure SQL
Azure SQL is essentially a general term for all SQL-based services on the Azure cloud and encompasses Azure SQL Database, Azure SQL Managed Instance, and SQL Server on Azure VM. Regardless of whether the data is being migrated from on-premise SQL Server databases to the Azure SQL Database or between Azure SQL services, certain steps remain consistent.
Initial Considerations and Planning
Before beginning the process of migration, there are certain factors to consider and choices to make:
- What Azure SQL service to migrate to: This depends on how much control is desired over the hosting environment and the SQL Server version compatibility. The options available are: Azure SQL Database, Azure SQL Managed Instance, and SQL Server on Azure VM.
- Is there a plan for the applications connecting to the databases? Will applications need to be re-pointed to the new location once the databases have been migrated?
- Are there any firewall rules that will need to be established to allow connections from the necessary sources?
- Is there room in your current budget to afford the Azure SQL service that meets your preference or requirements?
Compatibility Assessment
Once planning is complete, the next step is the assessment of database compatibility. The Data Migration Assistant (DMA) is a tool provided by Microsoft that will analyze SQL Server databases and provide recommendations that will guide you in making changes necessary for a successful Azure SQL migration.
Sinppet of running DMA:
Install-Module -Name SqlServer
Import-Module -Name SqlServer
Import-Module -Name SqlServerMigrationAssistant
# Initialize a new DMA assessment
$assessment = New-DmaAssessment -SourceSqlServerInstance “ServerName\InstanceName”
# Get the database list for specific instance
$DatabaseList = Get-DmaSqlInstanceDatabaseList -SqlServerInstance “ServerName\InstanceName”
# Add the databases to the assessment
$assessment.Databases.Add($DatabaseList)
# Start the DMA assessment
$assessment | Start-DmaAssessment
The compatibility results will provide details regarding any possible migration blockers, partially supported or unsupported features, and any differences in behavior between SQL Server and Azure SQL.
Migration Process
After we have identified and addressed the compatibility issues, we can perform the actual migration. Azure Database Migration Service (DMS) can be used for ‘offline’ (one-time, full-backup migration) and ‘online’ migration (continuous sync until cutover). A general workflow using Azure DMS would include creating an instance of DMS, creating a new migration project, and configuring the source and target details to start the migration.
Post Migration Steps and Monitoring
Once the migration is complete, it is important to validate your Azure SQL Database’s functionality. You’ll need to update any applications with the new connection string, check any dependent services, and perform a general functionality check.
The Azure SQL Database provides built-in monitoring and diagnostics, including Azure SQL Analytics and Azure Monitor Log Analytics, to help track performance and identify any issues regarding the health of the database.
In conclusion, mastery of Azure SQL services migration is a necessity for any aspiring Azure SQL Administrator preparing for the DP-300 exam. From planning, compatibility assessment, migration, to monitoring, each step has its nuances that one needs to grasp fully to ensure a smooth and successful process.
As Microsoft continues to add and develop tools and services for Azure, more streamlined and advanced methods for integrating Azure SQL services and migrating data will likely be introduced. Therefore, staying updated and consistently practicing the current methodologies will be key to passing the DP-300 exam and becoming an effective Azure SQL administrator.
Practice Test
True or False: Azure Migration service supports offline migration of your on-premises databases to Azure SQL.
- True
- False
Answer: True
Explanation: Azure Migration service supports offline (one-time) migrations, minimal downtime migrations, and continuous sync migrations.
Which of the following Azure services can be used to migrate your on-premises SQL Server databases to Azure SQL Database?
- a) Azure SQL Migration Assistant
- b) Azure Data Factory
- c) Azure Site Recovery
- d) Azure Web Apps
Answer: a) Azure SQL Migration Assistant
Explanation: Azure SQL Migration Assistant is designed specifically to migrate your on-premises SQL Server databases to Azure SQL Database.
Which of the following is not a step in the Azure migration process?
- a) Assessment
- b) Migration
- c) Restoration
- d) Optimization
Answer: c) Restoration
Explanation: The Azure migration process consists of four steps: Assessment, Migration, Testing, and Optimization.
True or False: You can only migrate databases less than 1TB in size using Azure Database Migration Service.
- True
- False
Answer: False
Explanation: Azure Database Migration Service doesn’t have a size limit for the databases that you can migrate.
In Azure Migration, Data Migration Assistant (DMA) helps to:
- a) Perform schema and data migration
- b) Identify migration blocking issues
- c) Identify feature parity issues
- d) All of the above
Answer: d) All of the above
Explanation: DMA performs all these tasks. It’s a key tool for simplifying the migration process.
What does the activity “validate migration setup” ensure in Azure SQL database migration?
- a) It confirms if the source and target servers are up and running
- b) It confirms if the user has sufficient privileges
- c) It confirms if the migration project name is correct
- d) Both a & b
Answer: d) Both a & b
Explanation: This activity ensures that source and target servers are operational and the user has the necessary privileges.
True or False: Azure Migration Service supports migration from SQL Server to Azure SQL Database Managed Instance.
- True
- False
Answer: True
Explanation: Azure Database Migration Service supports migrations from SQL Server on-premises, or on Azure VMs to an Azure SQL Database Managed Instance.
During the migration process, it is not necessary to perform resilience testing. True or False?
- True
- False
Answer: False
Explanation: Resilience testing is important to ensure the new system can handle peak loads and recover from failures.
What does the Data Migration Assistant replace?
- a) SQL Server Management Studio
- b) SQL Server Data Tools
- c) SQL Server Upgrade Advisor
- d) None of the above
Answer: c) SQL Server Upgrade Advisor
Explanation: DMA replaces SQL Server Upgrade Advisor, with the added feature of migration capability.
Can SQL Server Integration Services (SSIS) packages be migrated to Azure?
- a) Yes, without any changes
- b) Yes, but they require redesigning
- c) No, they cannot be migrated
- d) Only if they are not complex
Answer: a) Yes, without any changes
Explanation: SQL Server Integration Services (SSIS) packages can be migrated to Azure with the help of Azure Data Factory (ADF) and run without any changes.
True or False: Azure SQL services is a platform-as-a-service (PaaS) offering.
- True
- False
Answer: True
Explanation: Azure SQL services is a PaaS offering, which allows the developers to focus on the application development rather than on infrastructure and server maintenance.
What is the best practice for moving a large amount of data over a significant distance?
- a) Leveraging Azure Data Box
- b) Direct file copy
- c) Using an external hard drive
- d) Through email
Answer: a) Leveraging Azure Data Box
Explanation: Azure Data Box is designed specifically for such a scenario. You can move large amounts of data into Azure with ease using this service.
True or False: While migrating to Azure SQL database, downtime is unavoidable.
- True
- False
Answer: False
Explanation: Microsoft provides different migration methods that can minimize or avoid downtime completely depending on the strategy used.
What type of connectivity does Azure Database Migration Service (DMS) require to access the source SQL Server instance?
- a) Public connectivity
- b) ExpressRoute or Site-to-Site VPN connectivity
- c) DirectLine connectivity
- d) None of the above
Answer: b) ExpressRoute or Site-to-Site VPN connectivity
Explanation: DMS usually requires ExpressRoute or Site-to-Site VPN connectivity to access the source SQL Server instance.
Is it possible to migrate SQL Server failover cluster instances with Azure Site recovery (ASR)?
- a) Yes
- b) No
Answer: b) No
Explanation: Azure Site Recovery (ASR) doesn’t currently support migration of SQL Server Failover Cluster Instances (FCI) or Availability Groups. You need to use Azure Migration Service.
Interview Questions
What is Azure SQL Database?
Azure SQL Database is a fully managed platform as a service (PaaS) Database Engine that handles most of the database management functions such as upgrading, patching, backups, and monitoring without user involvement.
What is an Azure SQL Managed Instance?
Azure SQL Managed Instance is a fully managed SQL Server Database Engine hosted in the Azure cloud that provides near 100% compatibility with the latest SQL Server on-premises (Enterprise Edition) Database Engine.
What is Azure Database Migration Service (DMS)?
Azure Database Migration Service (DMS) is a fully managed service designed to enable seamless migrations from multiple database sources to Azure Data platforms with minimal downtime.
How do I migrate databases to Azure SQL Database or a SQL Managed Instance?
You can migrate databases to Azure SQL Database or a SQL Managed Instance using Azure Database Migration Service.
How to assess the readiness for migration to Azure SQL services?
Azure provides Data Migration Assistant (DMA) which provides the ability to detect compatibility issues, helps in migrating schema, data, uncontained objects, etc.
What is the purpose of database transaction logs during migration?
The transaction log captures all transaction activity and is critical for the proper functioning of the migration process, ensuring full data consistency and allowing a zero-downtime migration.
What is the Azure SQL Migration extension in Azure Data Studio?
Azure SQL Migration extension in Azure Data Studio provides a quick and easy way to migrate your databases to Azure SQL services. It provides a guided experience through every step of the migration process.
What network topology does Azure SQL Database Managed Instance operate in?
Azure SQL Database Managed Instance operates in a private network topology where the Managed Instance is placed within an Azure VNet and isolated from public internet.
How to choose the right service tier and compute size during migration to Azure SQL services?
The Azure SQL Database DTU and vCore resource models can be used to choose service tier and compute size. Factors to consider include size of the database, number of databases, and workload intensity.
What are some of the post-migration activities after migrating to Azure SQL services?
Post-migration activities include validating data, conducting performance tests, updating connection strings, and decommissioning old databases.
Can I use SQL Server Management Studio (SSMS) for managing Azure SQL services?
Yes, you can use SSMS, Azure Data Studio, and other SQL Server tools to manage Azure SQL Services.
How can I manage costs in Azure SQL Database and SQL Managed Instance?
You can manage costs by selecting the right pricing tier and compute size, consolidating databases with elastic pools or Managed Instance, and stopping or deleting unnecessary resources.
What is the role of Azure Active Directory with Azure SQL Database?
Azure Active Directory provides a comprehensive identity and access management solution for Azure SQL Database. It provides an alternative to SQL Server logins and offers password protection, multi-factor authentication, and other security features.
What is the availability model in Azure SQL Database and SQL Managed Instance?
Azure SQL Database and SQL Managed Instance use a high availability architecture that is designed to eliminate single points of failure. They use a technology similar to SQL Server Always On and provide a 99.995% availability SLA.
How can I monitor the performance of Azure SQL services?
Azure provides a suite of monitoring and diagnostics tools, including Azure Monitor, Azure SQL Analytics, and Azure SQLInsights. These tools can help you monitor performance, detect anomalies, and troubleshoot issues.
extutorials.com