Azure Database Migration Service Tutorial

Introduction

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. This tutorial will guide you through the entire process of setting up and using Azure DMS.

Prerequisites

Before you begin, make sure you have the following prerequisites:

• An active Azure subscription
• Access to the source database
• Access to the target Azure database
• Azure SQL Database or another supported target database
• Basic knowledge of databases and SQL

Creating an Azure Database Migration Service Instance

First, you need to create an instance of Azure Database Migration Service. Follow these steps:

1. Go to the Azure portal.
2. In the left-hand menu, select Create a resource.
3. In the Search the Marketplace box, enter Azure Database Migration Service.
4. Select Azure Database Migration Service from the results, and then click Create.
5. On the Create Migration Service page, provide the necessary information such as Subscription, Resource Group, Service Name, and Location.
6. Click Review + create and then Create.

Setting Up the Source and Target Databases

Before starting a migration project, you need to ensure that both source and target databases are properly set up.

Source Database

Ensure that your source database is accessible and that you have the necessary permissions to read from it. For example, if your source database is an on-premises SQL Server, make sure it can accept incoming connections.

Target Database

Ensure that your target database in Azure is created and configured. For instance, if you're migrating to an Azure SQL Database, ensure that the database is created and that you have the necessary permissions to write to it.

Creating a Migration Project

Once your DMS instance is set up, you can create a migration project.

1. In the Azure portal, navigate to your DMS instance.
2. Click on + New Migration Project.
3. Fill in the project details such as Project Name, Source Server Type, and Target Server Type.
4. Click Create and run activity.

Configuring the Migration Activity

Next, configure the migration activity by specifying the source and target databases, and the tables or data to migrate.

1. Select the source database and provide the necessary connection details.
2. Select the target database and provide the connection details.
3. Choose the tables and data to migrate.
4. Configure other settings such as Data Consistency and Schema Conversion as needed.
5. Click Save and then Run.

Monitoring the Migration

After starting the migration, you can monitor its progress in the Azure portal.

Go to the migration project and select the activity to view details such as the current status, progress percentage, and any errors encountered.

Completing the Migration

Once the migration is complete, verify that the data has been successfully migrated to the target database. Perform any necessary post-migration tasks such as data validation and application testing to ensure everything is functioning correctly.

Example: Migrating a SQL Server Database to Azure SQL Database

Troubleshooting

Here are some common issues and their solutions:

Connection Issues

Ensure that the source and target databases are accessible and that the firewall settings allow incoming connections.

Data Inconsistencies

Verify the data consistency settings and perform data validation checks after migration.

Error Messages

Review the error messages in the migration activity details and refer to Azure documentation for specific error codes and solutions.

Conclusion

Azure Database Migration Service simplifies the process of migrating databases to Azure, providing a seamless and efficient way to move your data with minimal downtime. By following this tutorial, you should be able to set up and execute database migrations using Azure DMS.