1.4 Cloud Migration Strategies
Key Takeaways
- The AWS Cloud Adoption Framework (CAF) organizes migration guidance into six perspectives: Business, People, Governance, Platform, Security, and Operations.
- The 7 Rs of migration are: Rehost (lift and shift), Replatform (lift, tinker, and shift), Refactor (re-architect), Repurchase (drop and shop), Retain, Retire, and Relocate.
- Rehost (lift and shift) is the fastest migration strategy — move applications as-is to the cloud with minimal changes.
- Refactoring (re-architecting) provides the greatest long-term cloud benefits but requires the most effort.
- The AWS Snow Family (Snowcone, Snowball, Snowmobile) enables physical data migration for large datasets.
Cloud Migration Strategies
Quick Answer: AWS offers the 7 Rs of migration: Rehost (lift and shift), Replatform (lift, tinker, shift), Refactor (re-architect), Repurchase (buy new SaaS), Retain (keep on-premises), Retire (decommission), and Relocate (move to VMware on AWS). The choice depends on business requirements, timeline, and desired cloud benefits.
AWS Cloud Adoption Framework (AWS CAF)
The AWS Cloud Adoption Framework (AWS CAF) provides guidance for organizations planning cloud migration. It organizes guidance into six perspectives:
Business Perspectives (Non-Technical)
| Perspective | Focus | Stakeholders |
|---|---|---|
| Business | Ensuring cloud investments accelerate business outcomes | CEO, CFO, COO, CIO |
| People | Human resources, staffing, organizational change management | HR, staffing, people managers |
| Governance | Organizational governance, risk management, compliance | CTO, CIO, CFO, CDO |
Technical Perspectives
| Perspective | Focus | Stakeholders |
|---|---|---|
| Platform | Designing and implementing cloud-ready architecture | CTO, technology leaders, architects |
| Security | Achieving confidentiality, integrity, and availability of data | CISO, compliance managers |
| Operations | Ensuring cloud services meet business needs day-to-day | IT operations, support managers |
On the Exam: Know the six perspectives and whether they are business-focused (Business, People, Governance) or technical-focused (Platform, Security, Operations).
The 7 Rs of Migration
When migrating workloads to the cloud, organizations use one of seven strategies known as the 7 Rs:
1. Rehost (Lift and Shift)
Move applications to the cloud without changes. Simply move from on-premises servers to EC2 instances.
- Effort: Low
- Benefit: Fast migration, immediate cost savings on data center operations
- Best for: Large-scale migrations with tight timelines
- Example: Move an on-premises web server directly to an EC2 instance
2. Replatform (Lift, Tinker, and Shift)
Move to the cloud with small optimizations that take advantage of cloud capabilities, without changing the core architecture.
- Effort: Low to Medium
- Benefit: Some cloud optimization without full re-architecture
- Best for: Applications that benefit from managed services
- Example: Migrate a database from self-managed MySQL on EC2 to Amazon RDS
3. Refactor / Re-architect
Redesign the application to be cloud-native, taking full advantage of cloud features like serverless and microservices.
- Effort: High
- Benefit: Maximum cloud benefits — scalability, performance, cost efficiency
- Best for: Applications with a strong business need to scale or add features
- Example: Break a monolithic app into microservices using Lambda, API Gateway, and DynamoDB
4. Repurchase (Drop and Shop)
Replace the existing application with a cloud-native SaaS product.
- Effort: Medium
- Benefit: Eliminates maintenance burden, access to new features
- Best for: Commercial off-the-shelf applications with SaaS equivalents
- Example: Move from an on-premises CRM to Salesforce, or from Exchange to Microsoft 365
5. Retain (Revisit)
Keep the application on-premises for now. Some applications may not be ready for migration due to compliance, recent investments, or complexity.
- Effort: None (for now)
- Best for: Applications with major compliance requirements or recent upgrades
6. Retire
Decommission the application. During migration assessment, you may discover applications that are no longer needed.
- Effort: Low
- Benefit: Eliminate unnecessary costs and complexity
- Best for: Duplicate, unused, or outdated applications
7. Relocate (Hypervisor-Level Lift and Shift)
Move infrastructure to AWS without purchasing new hardware, rewriting applications, or modifying operations. Specifically refers to migrating VMware workloads to VMware Cloud on AWS.
- Effort: Low
- Benefit: Fast migration for VMware environments
- Best for: Organizations heavily invested in VMware
Migration Tools and Services
| Service | Purpose |
|---|---|
| AWS Migration Hub | Central location to track migration progress across multiple tools |
| AWS Application Migration Service (MGN) | Automate lift-and-shift migrations of servers |
| AWS Database Migration Service (DMS) | Migrate databases to AWS with minimal downtime |
| AWS Schema Conversion Tool (SCT) | Convert database schemas between different engines |
| AWS Snow Family | Physical devices for large-scale offline data transfer |
| AWS DataSync | Automated data transfer between on-premises and AWS storage |
| AWS Transfer Family | SFTP, FTPS, FTP file transfers into AWS |
AWS Snow Family for Data Migration
For very large datasets where network transfer would take too long, AWS offers physical data transfer devices:
| Device | Storage | Use Case |
|---|---|---|
| AWS Snowcone | 8 TB usable (HDD) / 14 TB (SSD) | Small-scale edge computing and data transfer |
| AWS Snowball Edge Storage Optimized | 80 TB usable | Large data center migrations |
| AWS Snowball Edge Compute Optimized | 80 TB usable + powerful compute | Edge computing + data transfer |
| AWS Snowmobile | Up to 100 PB | Massive exabyte-scale data migrations |
On the Exam: If a question mentions transferring petabytes of data or mentions that network transfer would take months/years, the answer is likely AWS Snow Family (Snowball or Snowmobile).
A company wants to move its on-premises application to AWS as quickly as possible without making any code changes. Which migration strategy should they use?
Which AWS service provides a centralized location to track the progress of application migrations across multiple AWS and partner tools?
A company needs to transfer 80 TB of data to AWS. Their internet connection would take over 60 days for the transfer. Which solution should they use?
The AWS Cloud Adoption Framework (CAF) organizes guidance into six perspectives. Which of the following are the THREE business-focused perspectives?