Cloud Migration
What Is Cloud Migration?
Cloud migration is the process of moving an organization’s digital assets, including applications, data, workloads, and infrastructure, from on-premises environments, private data centers, or legacy hosting arrangements to cloud-based infrastructure managed by a public cloud provider. It encompasses the planning, execution, testing, and optimization of that transition.
Cloud migration is rarely a single event; it is a multi-phase programmed involving assessment and planning, workload prioritization, migration execution in waves, post-migration optimization, and ongoing cloud governance.
The Six Migration Strategies (The 6 Rs)
Rehost (Lift and Shift): Move applications to cloud virtual machines with minimal changes.
Replatform: Make targeted optimizations during migration to leverage cloud capabilities without full redesign. For example, replacing a self-managed database with a managed cloud database service.
Refactor/Re-architect: Redesign applications to cloud-native, leveraging microservices, containers, and serverless architecture.
Repurchase: Replace an existing application with a SaaS equivalent rather than migrating it.
Retain: Keep specific applications on premises because migration is not yet justified by cost, complexity, or compliance considerations.
Retire: Decommission applications that are no longer needed once migration decisions are evaluated.
Critical Success Factors in Cloud Migration
Migration projects that succeed share several characteristics: thorough discovery and dependency mapping before migration begins, phased execution that limits the scope of each wave, comprehensive testing of migrated workloads before production cutover, and clear rollback procedures for each migration step. Executive sponsorship and cross-functional involvement from IT, security, finance, and application owners are equally important.
Post-Migration Optimization
Successful migration is the beginning, not the end. Post-migration optimization rightsizes cloud resources, implements cost management policies, modernizes application architecture progressively, and establishes cloud governance practices that keep the environment secure, compliant, and cost-efficient over time.
Key Takeaways
- Cloud migration moves applications, data, and workloads from on-premises or legacy hosting to cloud infrastructure.
- The 6 Rs (Rehost, Replatform, Refactor, Repurchase, Retain, Retire) provide a strategic framework for evaluating each workload.
- Successful migration requires dependency mapping, phased execution, comprehensive testing, and clear rollback procedures.
- Post-migration optimization, rightsizing, and governance unlock the full cost and performance benefits of cloud hosting.
- Cloud migration is a multi-phase programmed, not a single event.