AWS Cloud Migration Part 1: On-Premises (VMware VM) to AWS Migration Strategy

Introduction:

Migrating from on-premises data centers to AWS is one of the most transformative initiatives organizations undertake to modernize their infrastructure, improve agility, and reduce operational costs. This is the first part of a three-part series exploring AWS migration methodologies across different scenarios. In this article, we’ll focus specifically on on-premises to AWS migrations, covering proven strategies, tools, and a detailed six-week implementation timeline.

Part 1:  On-premise(VMware VM) to AWS Mgiration

Part 2: AWS to AWS Migrations (Merging companies)

Part 3: Azure/GCP to AWS

Understanding the Rehost and Replatform

Before diving into the migration process, it’s essential to understand Rehost and Replatofrm, which provides strategic approaches for migrating applications to the cloud:

2. Rehost (Lift and Shift)
Lift and shift at the OS level. Applications are migrated from on-premises VMs to AWS EC2 instances using AWS Application Migration Service (MGN), with minimal or no code changes.

Best for:Quick migrations with tight timelines, reducing data center costs rapidly.

3. Replatform (Lift and Reshape)
This approach involves moving applications to the cloud while taking advantage of some cloud capabilities. Examples include adding Application Load Balancers (ALB) or migrating from VM-based SQL or Oracle databases to Amazon RDS.

Best for: Balancing speed with cloud optimization, gaining immediate benefits without full refactoring.

Part 1:  On-premise(VMware VM) to AWS Mgiration

Recommended Strategy: Combined Rehost and Replatform Approach

For large-scale on-premises to AWS migrations, the most effective strategy combines Rehost and Replatform methodologies. This hybrid approach enables organizations to:

– Migrate quickly using automated replication tools
– Optimize immediately by adopting AWS-managed services
– Reduce risk through proven migration patterns
– Maximize ROI by balancing speed with cloud-native benefits

Why Combine Rehost and Replatform?

Rehost alone gets you to the cloud quickly but misses opportunities for immediate optimization. Replatform alone can slow down migrations due to extensive planning and testing. By combining both strategies, you can:

1. Migrate compute workloads using Rehost (AWS MGN) for speed
2. Adopt managed services for databases (Amazon RDS), load balancing (ALB/NLB), and storage (Amazon EFS/S3)
3. Reduce operational overhead from day one
4. Lower total cost of ownership  through right-sizing and managed services

The Six-Week Migration Framework:

This proven methodology has been successfully used to migrate 1,200+ applications across federal and commercial customers. The framework is designed for migrating approximately 200 servers per Wave but can be scaled up or down based on your environment.

Week 1: Discovery and Planning

Objective: Understand your environment and create a comprehensive migration plan.

Key Activities:

1. Discover 200 servers using  existing CMDB or Third party tools or VMware RVTools
– Install discovery agents or use agentless discovery
– Collect server inventory, performance metrics, and network dependencies
– Identify operating systems, applications, and middleware

2. Map servers to applications
– Group servers by application and business function
– Document application owners and stakeholders
– Identify critical vs. non-critical applications
– Create application dependency maps

3. Gather infrastructure requirements:
– Compute: Determine EC2 instance types based on CPU, memory, and performance requirements
– Storage: Calculate EBS volume sizes, IOPS requirements, and S3 bucket needs
– Databases: Identify candidates for Amazon RDS migration (SQL Server, Oracle, PostgreSQL, MySQL)

– Load Balancers: Determine ALB/NLB requirements for web applications

4. Agree on cutover schedule
– Prioritize applications by business criticality
– Define maintenance windows for each environment (Dev, Stage, Test, Prod)
– Coordinate with application owners and stakeholders
– Establish success criteria and rollback procedures

5. Identify Replatform opportunities
– Database migrations to Amazon RDS
– File servers to Amazon EFS or FSx
– Load balancers to ALB/NLB
– Backup solutions to AWS Backup

Deliverables:
– Server inventory and application mapping
– Infrastructure requirements document
– Migration wave plan with cutover schedule
– Risk assessment and mitigation plan

Week 2: Prerequisites and Foundation

Objective: Build the AWS foundation and prepare the target environment.

Key Activities:

1. Create AWS accounts using AWS Organizations and AWS Control Tower
– Set up organizational units (OUs) for different environments
– Implement Service Control Policies (SCPs) for governance
– Configure consolidated billing
– Establish cross-account roles for migration tools

2. Set up networking
– Design and create VPCs with appropriate CIDR blocks
– Configure subnets across multiple Availability Zones
– Set up security groups and Network ACLs
– Establish AWS Direct Connect or Site-to-Site VPN connectivity
– Configure routing tables and NAT gateways

3. Provision Application Load Balancers (ALB)
– Create target groups for web applications
– Configure health checks and routing rules
– Set up SSL/TLS certificates using AWS Certificate Manager
– Configure listener rules and host-based routing

4. Configure Amazon RDS instances
– Provision RDS instances for database migrations
– Configure Multi-AZ deployments for high availability
– Set up automated backups and maintenance windows
– Create parameter groups and option groups
– Configure security groups for database access

5. Establish IAM roles and policies
– Create roles for AWS MGN replication servers
– Configure policies for CMF automation
– Set up cross-account access for migration tools
– Implement least-privilege access controls

Deliverables:
– AWS account structure with proper governance
– Network architecture with connectivity established
– ALB and RDS instances provisioned
– IAM roles and policies configured

Week 3: Preparation and Agent Installation

Objective: Prepare source servers and begin replication to AWS.

Key Activities:

1. Prepare all environment servers(Dev, Stage, Test, Prod)
– Validate server access and credentials
– Document application configurations
– Create pre-migration backups
– Verify network connectivity to AWS

2. Install AWS MGN agents on source servers using CMF automation
– Deploy agents via CMF orchestration
– Configure replication settings (bandwidth throttling, encryption)
– Verify agent connectivity to AWS MGN service
– Monitor agent installation status in CMF dashboard

3. Configure replication settings in AWS MGN
– Set replication server instance types
– Configure EBS volume types and encryption
– Define staging area subnet and security groups
– Set up replication throttling for bandwidth management

4. Validate network connectivity
– Test connectivity from source servers to AWS MGN endpoints
– Verify firewall rules and proxy configurations
– Confirm DNS resolution for AWS services
– Test data replication throughput

5. Begin initial data replication for all servers
– Monitor replication progress in AWS MGN console
– Track replication lag and data transfer rates
– Identify and resolve replication issues
– Ensure continuous replication is established

6. Test agent connectivity and replication status
– Verify all agents are reporting healthy status
– Confirm data is replicating to staging area
– Review CloudWatch metrics for replication performance
– Document any servers requiring remediation

Deliverables:
– All servers with MGN agents installed
– Continuous replication established for all servers
– Replication monitoring dashboard configured
– Issue tracking and remediation log

 Week 4: Development Environment Cutover

Objective: Execute the first cutover to validate the migration process.

Key Activities:

1. Perform Dev environment cutover
– Launch test instances from replicated servers in AWS MGN
– Apply launch templates with correct instance types and configurations
– Verify instances launch successfully in target VPC

2. Launch test instances from replicated servers
– Use AWS MGN launch settings for automated configuration
– Apply tags for cost allocation and resource management
– Configure instance metadata and user data scripts
– Verify EBS volumes are attached correctly

-Make Sure 3/3 Instances checks are healthy

-Perform the cutover of Dev Instances

3. Validate application functionality in AWS
– Test application startup and initialization
– Verify application logs for errors
– Confirm application services are running
– Test inter-server communication and dependencies

4. Configure ALB and target groups for Dev applications
– Register EC2 instances with target groups
– Configure health checks and thresholds
– Test load balancer routing and failover
– Verify SSL/TLS termination

5. Test database connectivity to RDS instances
– Migrate databases using AWS DMS or native tools
– Update application connection strings
– Test read/write operations
– Verify database performance and query execution

6. Document lessons learned and adjust processes
– Capture issues encountered and resolutions
– Update runbooks and procedures
– Refine launch templates and configurations
– Share findings with migration team

Deliverables:
– Dev environment successfully migrated to AWS
– Application functionality validated
– Updated migration runbooks
– Lessons learned document

Week 5: Perform the Test and Stage Cutover

-Repeat the same steps as Week 4

Week 6 : Prod Cutover

-Repeat the same steps as Week 4

Essential Tools for Large-Scale Migrations:

AWS Cloud Migration Factory (CMF)
Purpose: Enterprise migration orchestration and automation

Key Features:
– Centralized migration project management
– Automated agent deployment and management
– Wave-based migration planning
– Integration with AWS MGN and AWS DMS
– Custom workflow automation
– Reporting and analytics dashboard

Benefits:
– Reduces manual effort by 70%
– Standardizes migration processes
– Provides visibility across migration waves
– Enables parallel migrations at scale

AWS Application Migration Service (MGN)
Purpose: Continuous replication with minimal downtime

AWS Database Migration Service (DMS)
Purpose: Database replication and migration

Common Challenges and Solutions:

Challenge 2: Application Dependencies
Solution:
– Use AWS Application Discovery Service for dependency mapping
– Migrate applications in logical groups
– Test inter-application communication thoroughly
– Maintain network connectivity between on-premises and AWS during transition

Challenge 3: Database Migration Complexity
Solution:
– Use AWS DMS for continuous replication
– Leverage AWS Schema Conversion Tool for heterogeneous migrations
– Perform database migrations during maintenance windows
– Test database performance and query execution thoroughly

Challenge 4: Licensing Considerations
Solution:
– Review software licensing agreements for cloud compatibility
– Consider AWS License Manager for tracking
– Evaluate Bring Your Own License (BYOL) vs. License Included options
– Engage with software vendors early in the process

Conclusion:

Migrating from on-premises data centers to AWS is a transformative journey that requires careful planning, proven methodologies, and the right tools. By combining Rehost and Replatform strategies and leveraging enterprise-grade tools like AWS Cloud Migration Factory (CMF) and AWS Application Migration Service (MGN), organizations can migrate hundreds of servers in weeks while optimizing for cloud-native capabilities.

The six-week migration framework outlined in this article has been successfully applied to migrate over 1,200 applications across multiple federal and commercial customers. By following this proven methodology, maintaining focus on automation and best practices, and continuously learning from each migration wave, organizations can minimize risk, reduce downtime, and accelerate their path to cloud transformation.

In Part 2 of this series, we’ll explore AWS Account to AWS Account migrations, covering scenarios such as mergers and acquisitions, organizational restructuring, and multi-account consolidation.

In Part 3 we’ll dive into Multi-Cloud to AWS migrations, examining strategies for migrating workloads from Google Cloud Platform (GCP) and Microsoft Azure to AWS.

Contact Information:

If you need help with Migrations, we have a team of AWS professionals who can help in the Migrations using Cloud migration factory and AWS Transofrm for VMware. We have successfully performed migrations for several customers. Please reach out to us directly at accelerators@inversys.com.

Happy Coding: AWS Migrations

Additional Resources

– [AWS Application Migration Service](https://aws.amazon.com/application-migration-service/)
– [AWS Cloud Migration Factory](https://aws.amazon.com/solutions/implementations/cloud-migration-factory-on-aws/)
– [AWS Database Migration Service](https://aws.amazon.com/dms/)
– [AWS Well-Architected Framework](https://aws.amazon.com/architecture/well-architected/)
– [AWS Cloud Adoption Framework](https://aws.amazon.com/professional-services/CAF/)
– [AWS Prescriptive Guidance](https://aws.amazon.com/prescriptive-guidance/)
– [AWS Migration Competency Partners](https://aws.amazon.com/migration/partner-solutions/)

– [AWS Transform for VMware](https://aws.amazon.com/transform/vmware/)