AWS Transform MGN (formerly AWS Application Migration Service)

Overview

AWS Transform MGN moves physical, virtual, and cloud servers into native Amazon EC2 instances, making it a strong fit for teams rehosting workloads into AWS. Its appeal is continuous replication and coordinated cutover; the trade-off is that the migration destination and ongoing replication charges tie the choice closely to AWS.

For a broader category comparison, see our Cloud Migration Tools list.

Key features

Replication and migration paths

MGN copies source-server data continuously at the block level, converts it for AWS, and coordinates cutover with minimal downtime. Teams can use an agentic AWS Transform workflow or handle rehosting in the MGN console, switching between the two without losing progress. That flexibility suits migrations whose level of automation varies across workloads.

Sources include physical servers, VMware vSphere, Microsoft Hyper-V, other on-premises infrastructure, and other public clouds. MGN also supports moves across AWS Regions, Availability Zones, and accounts. Its hard boundary is x86 source servers and replication volumes of no more than 16 TB; workloads outside either limit need another approach.

Post-launch work and operations

Built-in and custom post-launch actions can configure disaster recovery, upgrade operating systems, convert licenses, or install the CloudWatch Agent. Server grouping into applications and waves lets teams coordinate launch, cutover, archival, and configuration at the server, application, or wave level. That organization is useful for larger programs, though it does not remove the need to plan and sequence the migration.

Monitoring integrates with Amazon CloudWatch, CloudWatch Events, CloudWatch Logs, and AWS CloudTrail. MGN requires TLS 1.2 or later and uses TLS and IAM for authentication; AWS recommends EBS encryption and limiting replication-server exposure to the public internet. AWS says the service retains certifications including FedRAMP High, HIPAA, PCI DSS, ISO, and SOC 1, 2, and 3. Support for installation or replication issues is limited to operating systems AWS lists as supported.

Pricing

MGN has a free period, not an unrestricted free service. The Free period plan costs nothing for 2,160 hours (90 days when used continuously) per source server, billed on service charges only. AWS infrastructure used for replication, testing, or cutover is charged separately. After the free period, continued replication is charged per hour, so long-running migrations can continue to incur service charges.

This period is best suited to a bounded migration with a clear schedule. Teams should include the separate AWS infrastructure costs and post-period hourly replication charges in their budget, rather than treating the 90-day allowance as the total cost.

Platforms

MGN is a SaaS service with API, Linux, web, and Windows platform support. AWS says it is available in commercial AWS Regions and both AWS GovCloud (US) Regions.

Who it's for

MGN is for organizations moving supported x86 servers into EC2, especially when they need continuous replication, coordinated cutover, and a way to manage related servers in application waves. Its post-launch actions also suit teams that want migration work to include selected operating-system, licensing, or disaster-recovery steps.

It is a poor fit for non-x86 sources, replication volumes above 16 TB, or teams seeking to rehost outside AWS. Operating-system support should also be checked when installation or replication assistance may be needed.

Pros and cons

• Pro: Continuous block-level replication and coordinated cutover support migration with minimal downtime.
• Pro: Teams can switch between the Transform workflow and MGN console without losing progress.
• Pro: Application and wave grouping, plus operations at multiple levels, help coordinate large migrations.
• Con: Only x86 source servers and volumes up to 16 TB are supported.
• Con: Replication, testing, and cutover infrastructure incur separate AWS charges, and continued replication is billed hourly after the free period.
• Con: Support for installation and replication issues is limited to supported operating systems.

Alternatives

• Google Cloud Migration Center is worth considering for free cost estimates and assessments, particularly when planning around Google Cloud; other Google Cloud products may still incur charges.
• Amazon Database Migration Service is a paid alternative with an AWS Free Tier offering $100 in credits and up to an additional $100 for activating foundational AWS services; credits last up to 12 months.
• AWS Schema Conversion Tool is a free option for schema conversion on 64-bit Windows, Fedora Linux, or Ubuntu Linux, rather than server rehosting.
• Flexera One IT Asset Management is another paid option, with custom pricing.
• Ora2Pg is free GPL v3 software for readers comparing database migration tools.
• pgloader offers a free Community plan for evaluating or non-critical use, with best-effort support.
• Google Migrate to Containers is free for migrating workloads to Google Cloud; other Google Cloud services used may incur charges.
• Striim offers a Developer plan capped at 25 million events per month and a Cloud plan with dedicated compute and networking.

Verdict

Choose AWS Transform MGN when the goal is to rehost supported x86 servers in EC2 and the project benefits from continuous replication, cutover coordination, and grouped migration operations. Look elsewhere if your sources exceed its architecture or volume limits, if you need a destination beyond AWS, or if separate infrastructure and continuing hourly charges do not fit the migration budget.