Application Migration Service
🧠 What Is AWS Application Migration Service (MGN)?¶
AWS MGN is a fully managed lift-and-shift (rehost) migration tool that replicates live servers (physical, virtual, or cloud-based) to AWS, allowing you to launch them as EC2 instances with minimal downtime.
✅ It uses continuous block-level replication and supports automated testing, cutover, and rollback.
🎯 Why Use AWS MGN?¶
| Benefit | Description |
|---|---|
| ✅ Minimal downtime | Continuous replication enables quick cutovers |
| ✅ Lift-and-shift made simple | No need to redesign or rewrite apps |
| ✅ Works across environments | Migrate from on-prem, VMware, Hyper-V, or other clouds |
| ✅ Automated testing | Perform launch validations before final cutover |
| ✅ Cost-efficient | Pay-as-you-go EC2, storage, and replication charges |
🧱 Supported Source Environments¶
| Environment | OS Support |
|---|---|
| VMware/Hyper-V | Windows Server, Linux (Red Hat, Ubuntu, etc.) |
| Physical servers | Windows/Linux |
| Other clouds | Azure, GCP, other AWS accounts |
⚙️ How It Works (Architecture)¶
[Source Server] --replication agent--> [Replication Server on AWS]
|
[Staging Area (EBS volumes)]
|
→ Launch as EC2 during cutover
Key Components:¶
-
Replication Agent: Installed on source server
-
Staging Area: Temporary EC2 + EBS volumes
-
Conversion Engine: Converts system to bootable EC2 instance
-
Launch Templates: Used to define instance configuration
🔁 Migration Flow (Step-by-Step)¶
-
Install agent on the source server
-
Data is replicated continuously to the staging area in AWS
-
You can test the launch (non-disruptive)
-
When ready → cutover to AWS (launch EC2)
-
Decommission source server
🛠️ Automation & Customization¶
| Feature | Description |
|---|---|
| Launch templates | Define EC2 instance type, subnet, security group |
| Tags | Apply tags automatically to launched instances |
| Post-launch actions | Install CloudWatch agent, join AD, run scripts |
| Rollback | Rollback if test/cutover fails |
🔐 Security¶
| Control | Description |
|---|---|
| IAM roles | Used for replication and launch permissions |
| TLS encryption | In-transit replication is encrypted |
| KMS encryption | Optional for EBS staging area volumes |
| VPC support | You choose subnets and security groups |
📋 Requirements¶
| Requirement | Details |
|---|---|
| Agent installed | On every source server |
| Outbound internet | Needed for agent to reach AWS endpoint (or use VPC endpoint) |
| Permissions | IAM role with mgn:*, ec2:*, cloudwatch:* |
🚨 Limitations¶
| Limitation | Notes |
|---|---|
| Not for containerized apps | Use ECS/EKS migration tools instead |
| No in-place OS conversion | e.g., Windows to Linux not supported |
| Replication only to AWS | Not multi-cloud |
| No Terraform resource yet | Not natively supported in Terraform |
💰 Pricing¶
| Resource | Cost Type |
|---|---|
| Replication server | EC2 cost (usually t3.medium) |
| Staging area (EBS) | Charged per GB-month |
| Launched EC2 | Standard EC2 pricing after cutover |
| Free tier | ✅ 90 days free for each source server |
❗ You do not pay for the agent or service usage itself.
🧪 Typical Use Case¶
| Scenario | AWS MGN Role |
|---|---|
| Legacy VM to AWS | Rehost entire app as-is |
| Data center evacuation | Mass migration of hundreds of servers |
| Application test/dev clone | Migrate QA copy to AWS for testing |
| Disaster recovery setup | Use MGN for DR replication |
✅ TL;DR Summary¶
| Feature | AWS MGN |
|---|---|
| Migration Type | Lift-and-shift (rehost) |
| Supported OS | Windows, Linux |
| Replication Method | Continuous block-level |
| Downtime | Minimal (for cutover only) |
| Cost | Free for 90 days/server, then EC2+EBS cost |
| Automation | Yes, with post-launch actions |
| Multi-cloud | ❌ AWS-only |
| Testing Supported | ✅ Yes (test launch) |
🔧 CLI Sample (AWS MGN)¶
Install agent on Linux:
sudo ./aws-replication-agent installer \
--aws-access-key-id YOUR_KEY \
--aws-secret-access-key YOUR_SECRET \
--region us-east-1