How to Migrate AWS VMs to Azure: A Step-by-Step Guide

Windows enthusiasts and IT pros, gather around—today we’re unpacking a comprehensive tutorial on how to migrate Amazon Web Services (AWS) virtual machines (VMs) to Microsoft Azure using the powerful Azure Migrate: Server Assessment and Modernization tool. Whether you’re managing a hybrid cloud environment or planning a full-on transition, this guide will equip you with detailed insights and step-by-step instructions to make your migration journey a success.
In this article, we’ll break down the complete process from discovery and assessment to the deployment of replication appliances and test migrations. We’ll also explore the key technical components involved along with practical tips to ensure that your VM migration goes off without a hitch.

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1. The Roadmap to Migration​

Before diving into the nuts and bolts, let’s set the stage with the three core phases of the process:

• Discover & Assess: Verify prerequisites, evaluate performance, and right-size your AWS instances for migration.
• Prepare & Deploy: Configure both AWS and Azure environments, set up the replication appliance, and install essential tools.
• Test & Migrate: Run a test migration to validate the move and then perform the full migration for your AWS VMs to Azure.

At its heart, the process involves treating your AWS instances as physical servers—providing a familiar, yet robust transition path.

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2. Discovery & Assessment: Laying the Foundation​

Before you even think about moving workloads, you need to fully understand your current environment. This initial discovery phase is crucial as it helps assess which VMs are ready and how they’ll perform on Azure.

Key Assessment Steps:​

• Enable Password Authentication:
  AWS instances, by default, may not have password authentication enabled, hindering the discovery process. For Windows machines, ensure that WinRM is set up on port 5985 for remote management. Linux machines involve modifying the sshd_config file to enable password authentication and potentially allowing root login if required.
• Compatibility Check:
  Use commands like hostnamectl or uname -a on Linux to verify that your operating system is supported. Keep in mind, the migration treats these as physical servers, so checking your OS and kernel details is vital.
• Right-Sizing:
  The assessment not only verifies compatibility but also suggests optimal sizing for your Azure VMs. This ensures that you don’t over-provision resources—and helps in estimating potential run costs in Azure.

By performing these checks, you create a clear blueprint of your AWS environment, which simplifies planning for Azure migration.

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3. Preparing Azure: Setting Up Your Migration Environment​

Migrating to Azure isn’t as simple as a one-click process—it demands careful preparation of your Azure environment. This includes setting up an Azure Migrate project and ensuring your Azure account has the right permissions.

Crucial Preparatory Tasks:​

• Creating an Azure Migrate Project:
  Your account will need Contributor or Owner permissions to create a project. If you’re a newcomer to Azure, your free account should suffice, but do verify your IAM settings, especially if you’re operating within a larger organization.
• Assigning the VM Contributor Role:
  This role is essential because it grants your account the ability to create VMs, provision managed disks, and plan the networking aspects that the migration demands.
• Networking Requirements:
  Choose the Azure virtual network where your migrated VMs will reside. The replication appliance, which we’ll discuss next, demands specific networking configurations—ensuring communication over ports HTTPS 443 and TCP 9443.

Taking these steps in Azure sets the stage for a smooth transition and ensures that all the necessary resources are in place before the heavy lifting begins.

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4. Deploying the Replication Appliance: The Heart of the Migration​

The replication appliance is the engine room of your migration project. This appliance handles data replication from AWS to Azure, incorporating several key components:

Components of the Replication Appliance:​

• Configuration Server:
  Manages communication between AWS and Azure while coordinating replication efforts.
• Process Server:
  Optimizes data through caching, compression, and encryption before sending it to Azure’s cache storage account.

Setting It Up:​

• Prepare an EC2 VM:
• The replication appliance must run on a separate instance (ideally within the same VPC as your AWS VMs) on Windows Server 2012 R2 or 2016.
• Configure the necessary security group rules to allow communication on the specified ports.
• Download & Install:
• From your Azure Migrate project, download the replication appliance installer along with the registration key (valid for five days).
• Run the installer on your prepared EC2 VM, and follow the wizard for configuration.
• A passphrase generated during setup is critical; make sure to save it as you will need it when installing the Mobility service agent.
• Finalizing Registration:
• Complete the registration process in the Azure portal, which finalizes the appliance’s setup and prepares it for communicating with your AWS VMs.

The replication appliance is the linchpin that ensures data integrity and smooth transfer during the migration process. Its correct configuration is essential for minimizing downtime and achieving efficient replication.

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5. Mobility Service: Installing the Agent on AWS VMs​

The Mobility service agent is a vital component that must be installed on each AWS VM you wish to migrate. Without it, the replication appliance won’t be able to pull the necessary data.

Approaches to Install the Mobility Agent:​

• Manual Installation:
  For both Windows and Linux machines, you’ll extract the installer and run it on the AWS VM. For Linux, this process involves executing a script to install the agent, then registering it using the passphrase from the replication appliance.
• Management Tools:
  Consider leveraging AWS System Manager or System Center Configuration Manager if your organization already employs these tools. Other options include Azure Arc for servers or custom script extensions.

Once installed, the Mobility service continuously replicates data (initial and subsequent delta replications), ensuring that the AWS VM state is mirrored in Azure.

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6. Testing the Waters: Running a Test Migration​

Before committing to a full migration, a test migration is highly recommended. This step is akin to a dress rehearsal—ensuring that all systems are "green" before going live.

Why Run a Test Migration:​

• Validation of Settings:
  Verify that the replication process works as expected without disrupting operations on AWS.
• Troubleshooting:
  Identify potential issues, whether they’re related to boot configurations, network settings, or compatibility problems.
• Simulated Environment:
  Test migrations typically deploy the replicated data to a nonproduction virtual network in Azure, making it a safe way to confirm that the AWS VM will behave properly under Azure’s environment.

After testing, if issues arise, you can re-run the necessary assessments and adjustments before proceeding with the full migration.

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7. Full Migration & Monitoring​

Once the test migration validates your setup, the next step is to perform the full migration. From that point, your AWS VMs begin replicating continuously, and you can monitor progress directly from the Azure portal.

Monitoring Tools & Techniques:​

• Portal Notifications:
  Keep an eye on the job status through notifications in the Azure portal.
• Incremental (Delta) Replication:
  After the initial replication, only the changes in the data are replicated—this optimizes the process and minimizes network load.
• Job Tracking:
  The replication appliance provides detailed logs and status updates. Monitoring these can help ensure that your migration stays on schedule.

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Conclusion: Navigating the Migration Maze​

Migrating AWS VMs to Azure using Azure Migrate: Server Assessment is a detailed process, but with careful planning and execution, it’s entirely manageable. By following a structured path—from discovery and assessment to replication appliance deployment, agent installation, and test migrations—you can ensure a smooth transition.
For Windows users and IT administrators alike, this tutorial offers a window into the complexities of modern migration strategies while shedding light on important technical details. If you’re facing similar challenges or need practical advice on cloud migrations, this comprehensive guide is a great starting point to read, learn, and apply cutting-edge migration techniques.
Feel free to share your experiences or ask questions in the comments—we’re all in this tech journey together!
Happy migrating!

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Source: Medium https://medium.com/%40christopher.suffi/discover-assess-and-migrate-amazon-web-services-aws-vms-to-azure-9ce24148ef92/