AWS Cloud Migration: CAF, 7 Rs & Migration Services Cheatsheet
1. AWS Cloud Adoption Framework (AWS CAF) – 6 Perspectives
The AWS CAF helps organizations assess cloud readiness and build a structured roadmap for digital transformation. It divides capabilities into Business and Technical perspectives.
| Perspective |
Category |
Primary Focus |
Key Stakeholders & Capabilities |
| Business |
Business |
Align cloud investments with business goals and drive value realization. |
Business managers, finance, strategy; Data monetization, portfolio management |
| People |
Business |
Bridge technology and business by driving organizational change and cloud fluency. |
HR, leadership; Culture evolution, cloud skills, change acceleration |
| Governance |
Business |
Coordinate cloud initiatives while managing risks, budgets, and compliance. |
CIO, CFO, risk managers; Cloud financial management (FinOps), risk assessment |
| Platform |
Technical |
Architect scalable enterprise platforms and modernize existing workloads. |
CTO, architects; CI/CD, IaC, modern app development, platform engineering |
| Security |
Technical |
Ensure data confidentiality, integrity, and availability in the cloud. |
CISO, security team; Identity/access management, threat detection, data protection |
| Operations |
Technical |
Deliver and maintain cloud services to meet operational business requirements. |
IT operations, site reliability engineers; Observability, patch management, incident management |
2. The 7 Migration Strategies (The 7 Rs)
| Strategy |
Alias / Description |
Effort & Cost |
Ideal Use Case & Exam Keyword Triggers |
| Rehost |
"Lift and Shift" |
Low |
Move servers/VMs to AWS as-is without architectural changes. Trigger: "Move quickly", "minimal code changes", "tight datacenter exit deadline". |
| Relocate |
"Hypervisor Lift & Shift" |
Low |
Move a cluster of VMs (e.g., VMware) or containers to AWS without changing code or OS. Trigger: "VMware Cloud on AWS", "no host re-configuration". |
| Replatform |
"Lift, Tinker, and Shift" |
Medium |
Make minor optimizations to leverage managed services without changing core code. Trigger: "Move self-hosted DB to Amazon RDS", "use managed platform". |
| Repurchase |
"Drop and Shop" |
Variable |
Replace an existing application with a third-party SaaS product. Trigger: "Switch to SaaS", "buy commercial software from AWS Marketplace". |
| Refactor / Re-architect |
"Cloud-Native Rewrite" |
Highest |
Completely redesign application code to use cloud-native features. Trigger: "Microservices", "serverless (Lambda)", "maximum agility & scalability". |
| Retain |
"Keep As-Is" |
Zero |
Keep applications in the source on-premises environment. Trigger: "Not ready for migration", "recently upgraded", "legacy compliance block". |
| Retire |
"Decommission" |
Zero |
Turn off applications that are no longer needed or providing business value. Trigger: "Identify unused IT assets", "decommission legacy system". |
- AWS Application Migration Service (AWS MGN): Primary tool for Rehosting physical, virtual, or cloud servers to EC2 with block-level replication and minimal downtime.
- AWS Database Migration Service (AWS DMS): Migrates databases to AWS with zero downtime.
- Homogeneous Migration: Same DB engine (e.g., MySQL to MySQL) $\rightarrow$ Use AWS DMS alone.
- Heterogeneous Migration: Different DB engines (e.g., Oracle to Aurora) $\rightarrow$ Use AWS Schema Conversion Tool (SCT) first, then AWS DMS.
- AWS Snow Family (Snowcone, Snowball Edge, Snowmobile): Physical hardware devices for offline, petabyte/exabyte-scale data transfers where internet bandwidth is limited.
- AWS DataSync: Automated online data transfer between on-premises storage (NFS/SMB) and AWS storage (S3, EFS, FSx).
- AWS Migration Hub: Single dashboard to track and monitor migration progress across multiple AWS and partner tools.
Common Target Workload Selection
- Relational Database (SQL): Amazon RDS or Amazon Aurora (Note: Aurora only supports MySQL & PostgreSQL; SQL Server on EC2 is often used for custom licensing/cost tuning).
- NoSQL Database: Amazon DynamoDB (Key-value / JSON document store).
- Low-Latency Shared Files: Amazon EFS (Linux file system) or Amazon FSx.
- Low-Cost Data Archiving: Amazon S3 Glacier (designed for long-term cold storage; incurs retrieval fees and lead times).
4. Top Exam Traps & Distractors
- CAF vs. Well-Architected Framework:
- AWS CAF: Focuses on organizational readiness, capabilities, and strategy (6 Perspectives).
- Well-Architected Framework: Focuses on technical architecture best practices for workloads (6 Pillars).
- Rehost vs. Replatform vs. Refactor:
- Moving a VM as-is to EC2 $\rightarrow$ Rehost.
- Moving a DB to RDS without rewriting the app $\rightarrow$ Replatform.
- Rewriting a monolithic app into Lambda functions $\rightarrow$ Refactor.
- AWS DMS + AWS SCT: If converting database engines during migration, you must use the Schema Conversion Tool (SCT) to convert the schema before using DMS to replicate the data.