What is Cloud Migration?
Cloud migration is the process of transferring applications, data, and workloads from on-premises infrastructure or another cloud to a target cloud platform.
Cloud migration is the systematic transfer of digital assets including applications, databases, and entire workloads from local data centers or an existing cloud provider to a new cloud environment. The target is typically a public cloud platform such as Amazon Web Services (AWS), Microsoft Azure, or Google Cloud Platform (GCP). Organizations undertake cloud migration to reduce capital expenditure, improve scalability, and access advanced services like machine learning and serverless computing.
The process generally follows a structured methodology. It begins with discovery and assessment of the current environment, including dependencies and performance baselines. Teams then select a migration strategy from the six common patterns: Rehost (lift and shift), Replatform (lift, tinker, and shift), Refactor (re-architect), Repurchase (move to a SaaS product), Retire (decommission unused assets), and Retain (keep on-premises for now). The actual migration uses tools like AWS Migration Hub, Azure Migrate, or third-party software to replicate data, synchronize changes, and cut over traffic. Post-migration validation ensures performance, security, and cost targets are met.
Cloud migration sits within the broader context of digital transformation and IT modernization. It requires careful planning to address network latency, data sovereignty, compliance (e.g., GDPR, HIPAA), and application compatibility. Many enterprises adopt a phased approach, migrating non-critical workloads first. The process often leads to ongoing optimization, such as right-sizing instances and adopting managed services. Cloud migration is distinct from cloud repatriation, where workloads move back on-premises, and from hybrid cloud strategies that maintain a mix of environments.
Key facts
- Common migration strategies are the 6 Rs: Rehost, Replatform, Refactor, Repurchase, Retire, Retain.
- Tools like AWS Migration Hub and Azure Migrate automate discovery, assessment, and replication.
- Phased migration reduces risk by moving non-critical workloads before production systems.
- Security and compliance requirements must be validated before, during, and after the migration.
- Cost optimization is a primary driver, but unexpected data transfer fees can occur.
How it works in practice
Related terms
References
More in Cloud Computing
Availability Zone
An Availability Zone is an isolated, fault-tolerant data centre within a cloud region, with independent power, cooling, and networking to prevent single points of failure.
Cloud Bill Shock
Cloud bill shock is an unexpectedly high invoice caused by unmonitored resource usage, often from data egress fees, autoscaled compute instances, or orphaned storage volumes.
Cloud Cost Optimization
Cloud cost optimization is the continuous practice of measuring, analyzing, and reducing cloud spending through rightsizing instances, purchasing reservations, and eliminating waste.
Cloud-Native
Cloud-native is an approach to building and running applications that exploit the elastic, distributed, containerized, and immutable nature of modern cloud infrastructure.
Edge Location
An edge location is a data center or point of presence deployed by a cloud provider at the network edge to serve content and run compute workloads closer to end users than a full parent region.
Egress Fees
A per-gigabyte charge imposed by cloud providers on network traffic that leaves their data center, availability zone, or internet boundary.
FaaS
FaaS (Function as a Service) is a cloud computing model where users deploy small, stateless functions that the provider executes on demand, automatically scaling and billing per invocation.
Hybrid Cloud
Hybrid cloud is a computing environment that combines a public cloud with a private or on-premises data center, connected by secure networking to enable workload portability and unified management.
IaaS
Infrastructure as a Service (IaaS) is a cloud computing model that provides on-demand access to virtualized compute, storage, and networking resources, which the customer configures and manages from the operating system upward.
Lift and Shift
Lift and shift is a cloud migration strategy that moves on-premises applications and data to cloud infrastructure with minimal or no changes to the original architecture.