AWS MGN (Application Migration Service)
Automated lift-and-shift migration service for moving applications to AWS
Moving your applications from on-premises servers to AWS is like moving houses; you could pack everything yourself, rent a truck, and hope nothing breaks, or you could hire professional movers. AWS MGN is the professional moving service for servers. You install a small agent on your source servers, and MGN continuously replicates them to AWS in the background. When you're ready to migrate, you click a button, and MGN launches identical copies in AWS with minimal downtime. It's like having a perfect clone of your server ready to go, so you can test it, tweak it, and switch over when you're confident.
MGN (formerly CloudEndure Migration) performs continuous block-level replication of source servers to AWS. The MGN agent installed on source servers captures disk changes and replicates them to a staging area (lightweight EC2 instances with EBS volumes). When you launch a test or cutover, MGN provisions target EC2 instances matching your source server specs, attaches the replicated EBS volumes, and boots the instances.
Key Capabilities
Key features: automated conversion (adjusts drivers, network settings for AWS), non-disruptive testing (test migrations without affecting production), and cutover orchestration.
Gotchas & Constraints
Gotcha #1: MGN replicates everything including OS, applications, and data. Ensure source servers are clean (no malware, unnecessary software). Gotcha #2: Initial replication can take hours or days depending on data size and network bandwidth; plan accordingly. Constraints: Supports Windows and Linux, but not all OS versions. Requires network connectivity from source to AWS (VPN or Direct Connect for large migrations).
A financial services company needs to migrate 200 servers from their data center to AWS before their lease expires in 6 months. Manual migration would require rebuilding each server, reinstalling applications, and migrating data, an estimated 18 months of work. They use AWS MGN, installing agents on all 200 servers. MGN replicates servers continuously while they remain in production. They test migrations in waves: launch test instances in AWS, validate applications work, then cutover production traffic. For critical servers, cutover downtime is under 10 minutes (final sync + DNS switch). They migrate 50 servers per month, completing the project in 4 months. MGN handles OS conversion, network reconfiguration, and ensures data consistency.
The Result
on-time migration, minimal downtime, and 70% reduction in migration effort.