Migrate Droplet from DO to AWS using AWS Migration Application Service (MGN)

Source: Dev.to

Preparation

Before you begin, make sure you have the following information and permissions:

• AWS Account – activated and authorized to create EC2, VPC, and MGN resources.
• DigitalOcean Account – root SSH access to the Droplet you want to migrate.
• AWS IAM User – an IAM user with the AWSApplicationMigrationAgentInstallationPolicy permission. Use this user to obtain an Access Key ID and Secret Access Key.

Step 1: Initialize the VPC

1. Open the AWS console and navigate to VPC → Create VPC.
2. Configure the VPC with the desired CIDR block, name, and other settings.
3. After creation, verify that the VPC appears in the VPC dashboard.

Step 2: Initialize AWS MGN

If this is your first time using MGN in the selected region:

1. Log in to the AWS console.
2. Search for AWS Application Migration Service and select it.
3. Click Get started to initialize the service.

Replication Settings

1. On the Replication settings screen, click Edit.

2. Configure the template for the replication instance:

   • Staging area subnet – select the subnet in the VPC that will receive temporary data.
   • Replication Server instance type – choose an instance type comparable to your DigitalOcean Droplet.
   • Leave the remaining options at their defaults.

3. Click Save template.

Launch Template

1. Go to Launch template → Edit.
2. Uncheck Activate instance type right‑sizing to customize the configuration.
3. Select the desired security group (SG) and instance type, then save.

Step 3: Install the Replication Agent on the DigitalOcean Droplet

Note: Back up your Droplet before proceeding.

1. SSH into the Droplet as root and, if needed, change the root password.
2. In the AWS MGN console, open Source servers and click Add server.
3. Choose the operating system (e.g., Linux) and copy the two commands shown by AWS.

# Download the installer
sudo wget -O ./aws-replication-installer-init https://aws-application-migration-service-ap-southeast-1.s3.ap-southeast-1.amazonaws.com/latest/linux/aws-replication-installer-init

# Make it executable and run it (replace the region if needed)
sudo chmod +x aws-replication-installer-init
sudo ./aws-replication-installer-init --region ap-southeast-1

4. When prompted, enter the Access Key ID and Secret Access Key you created earlier, and select the disk to sync.
5. The installation takes ~5‑10 minutes; the replication agent will then begin replicating data to AWS.

Step 4: Configure Launch Settings (Target Server)

1. After the agent is installed, the Droplet appears in Source servers with an Initial Sync in progress.

2. Click the server name, then select the Launch settings tab.

3. In the EC2 Launch Template section, click Edit and adjust the following:

   • Instance Type – e.g., t3.medium, c5.large, etc.
   • Subnet – choose the subnet where the EC2 instance will run.

4. Save the launch template.

Step 5: Launch Test Instance

5.1 Launch Test Instance

1. Wait until the replication status shows “Ready for testing” and Data replication is “Healthy.”
2. Select the server → Test and cutover → Launch test instances.
3. The lifecycle status changes to “Test in progress.”

5.2 Verify Test Instance

1. After the test instance launches, MGN displays a notification.
2. In the EC2 console, you’ll see an instance with a hostname similar to the source server.
3. To view the launch log, go to MGN → Launch history.

5.3 Launch Cutover

1. In MGN, select the server → Test and cutover → Mark as Ready for cutover (this deletes the test instance).
2. When the lifecycle shows “Ready for cutover,” click Launch cutover instances.

5.4 Verify the Cutover Process

• The new EC2 instance is created from the snapshots replicated earlier and follows the configuration defined in the launch template.
• Confirm that the application and data are functioning as expected on the EC2 instance.

5.5 Finalize Cutover

• Once verification is complete, you can decommission the original DigitalOcean Droplet.

Further troubleshooting and lessons learned from the migration will be covered in a later article. Thank you for reading.