What is Cloud Migration?

The shift of digital assets—including data, applications, and IT infrastructure—from traditional on-premises data centers to cloud provider infrastructure represents a fundamental change in how organizations operate. Historically, companies maintained their own IT infrastructure locally, often managing thousands of databases, applications, and software systems within their facilities. Through cloud migration, these workloads transition to cloud provider systems in a structured, minimally disruptive manner. Organizations that undertake this shift typically establish a migration strategy that involves prioritizing workloads, detailed planning, and rigorous testing to ensure systematic movement of operations to the cloud.

What are the benefits of cloud migration?

Initially, organizations deployed only new applications to cloud platforms while maintaining legacy systems on-premises. However, as awareness of cloud infrastructure advantages grew, interest in migration accelerated. Organizations now recognize numerous benefits that drive adoption decisions.

Cost efficiency

Transitioning to public cloud infrastructure can generate substantial financial benefits. Shifting to the cloud eliminates expenses associated with maintaining physical data centers, including hardware costs, electrical consumption, and cooling infrastructure. Beyond infrastructure savings, migration allows organizations to redirect skilled personnel away from routine data center management toward strategic business initiatives, representing significant human resource cost reductions. Cloud provider pricing typically undercuts the expense of operating an internal data center. The consumption-based pricing model—where organizations pay only for resources actually used—enables flexible scaling aligned with business fluctuations. Additionally, cloud providers offer diverse pricing structures with substantial free tier options, allowing companies to select the most economical solution for their circumstances.

Scalability

Cloud infrastructure's built-in scalability represents a significant operational advantage. Organizations can dynamically modify IT resource allocation in response to changing workload demands without undertaking expensive and time-intensive infrastructure expansion projects. This flexibility ensures applications maintain peak performance during high-demand periods while avoiding resource waste during slower periods. Cloud providers typically offer a broader selection of services and capabilities than most organizations can develop independently. The cloud environment enables faster innovation and quicker adaptation to evolving market dynamics.

Security

Established cloud providers including Amazon Web Services (AWS) allocate substantial resources toward infrastructure security and data protection. These investments result in comprehensive security capabilities, encompassing data encryption, multi-factor authentication (MFA), and continuous security assessments. Redundant backup systems and disaster recovery solutions safeguard digital assets across the platform. Cloud providers maintain responsibility for securing the cloud infrastructure itself, while organizations bear responsibility for establishing appropriate configurations and access restrictions to secure their data within the cloud environment.

Performance

Cloud migration provides access to cutting-edge server and network infrastructure, enabling faster data processing and improved application responsiveness. Organizations benefit from globally distributed data centers and content delivery systems that serve users from geographically proximate locations, reducing latency and improving response times. Cloud-hosted applications and services consistently operate at maximum efficiency, enhancing end-user experience, increasing operational productivity, and delivering competitive advantages.

Sustainability

Cloud providers achieve superior energy efficiency compared to conventional data centers through their operational scale. They optimize server utilization rates, deploy energy-efficient hardware, and implement sophisticated cooling systems. Organizations migrating to the cloud realize cost advantages while simultaneously reducing their environmental footprint.

What are cloud migration strategies?

Organizations employ multiple cloud migration strategies for successful cloud adoption. The appropriate strategy depends on factors including business requirements, technical obstacles, and desired migration outcomes.

Rehosting

Rehosting transfers application components to the cloud with minimal or no modifications. This approach—commonly called lift and shift—relocates existing infrastructure to cloud systems without architectural changes. This represents the fastest migration path since it avoids application redesign. However, legacy application architectures may not fully leverage cloud capabilities, potentially limiting the realization of cloud benefits.

Relocating

Also termed lift and optimize, relocation moves applications to the cloud with limited initial modifications. Following deployment, applications may transition to cloud-native services. For instance, a relocated database might shift from a hosted virtual machine (VM) to a managed database service. This strategy captures some cloud-native advantages without requiring extensive upfront refactoring.

Refactoring

Refactoring redesigns applications to fully exploit cloud-native capabilities. This might involve converting monolithic systems into microservices or substituting existing components with fully managed cloud services. Organizations typically select this approach when they require new functionality, improved scalability, or enhanced performance that the current application architecture cannot deliver.

Replatforming

Replatforming—known as lift, tinker, shift—occupies a middle position between rehosting and refactoring. Organizations implement targeted optimizations to leverage cloud capabilities without the extensive modifications required by refactoring. Specific application components transition to cloud services offering advanced features with customization options. For example, replacing a legacy, labor-intensive data management system with an autonomous cloud database service that provides automatic updates and integrated machine learning capabilities.

Repurchasing

Repurchasing involves switching to a different product and discontinuing or replacing existing software licenses. An organization might transition from traditional on-premises virtual desktop infrastructure (VDI) to a fully managed cloud-based VDI solution. This strategy emphasizes acquiring cloud-native applications while retiring legacy systems.

Retiring

Retiring deactivates assets that are no longer necessary or have become obsolete in contemporary cloud computing contexts. Unlike repurchasing, which emphasizes replacement, retiring focuses on decommissioning outdated infrastructure. Eliminating unnecessary assets allows organizations to concentrate resources on priorities, reducing migration expenses and simplifying the migration process.

Retaining

Retaining—also called revisiting—involves delaying migration for certain applications. This approach suits applications that recently underwent major upgrades or lack clear migration justification. Organizations may maintain these applications on-premises or in their current environment until compelling reasons for migration emerge. Periodic reassessment of retained applications determines appropriate migration timing.

What are the types of cloud migration?

Cloud migration manifests in various forms aligned with organizational objectives and digital transformation aspirations.

Database migration

Database migration transfers databases between environments—from on-premises to cloud, between cloud providers, or to newer database engines. This process demands careful data mapping and schema transformation to prevent data corruption. Migration planning must minimize operational downtime. Common approaches include:

  • Replication-based migration maintains synchronized databases by continuously duplicating data from source to target
  • Full export transfers source data to secure media shipped to the cloud provider for target import
  • Extract, convert schema, and load operations transfer data to cloud databases via secure network connections

Application migration

Application migration relocates existing applications from on-premises systems or one cloud environment to another. Migration approaches vary:

  • Rehosting applications with minimal modifications
  • Replatforming to leverage cloud-native capabilities such as managed databases or serverless computing
  • Refactoring entirely to adopt microservices-based design

Successful migration depends on code compatibility, performance optimization, and cloud service integration. Legacy mainframe applications—frequently written in COBOL or comparable outdated languages—present the greatest complexity. Ensuring mission-critical functions continue uninterrupted requires extensive testing and phased migration approaches.

Hybrid migration

Hybrid cloud migration transfers certain workloads to the cloud while maintaining others on-premises. Organizations employ this approach when they wish to preserve existing infrastructure while accessing cloud advantages. Peak workloads may migrate to the cloud for dynamic scaling. Hybrid architectures utilize orchestration tools to enable seamless communication between disparate environments. Hybrid migration frequently represents the initial phase of comprehensive migration strategies.

Data center migration

Data center migration relocates entire on-premises infrastructure—encompassing servers, storage, networking, and applications—to cloud platforms. This migration type typically incorporates all previously outlined migration strategies and demands meticulous planning and oversight. Complexity varies based on data center scale, security requirements, and legacy system compatibility with cloud services. Organizations pursue this migration to decrease operational expenses, enhance scalability, and strengthen disaster recovery capabilities.

Cloud-to-cloud migration

Cloud-to-cloud migration occurs when organizations transfer workloads between different cloud service providers. Motivations include cost optimization, superior performance, regulatory compliance, or enhanced service offerings. Organizations must carefully manage data transfer speed, downtime risks, and potential vendor lock-in concerns.

What are the steps in cloud migration?

While each organization's cloud migration path differs, AWS structures the migration process into three primary phases. These phases provide a flexible framework adaptable to specific organizational circumstances.

Assess

Cloud migrations commence with comprehensive evaluation of existing IT assets, encompassing applications, workloads, and data. The assessment phase includes:

  • Identifying business goals and migration objectives
  • Evaluating technical requirements and application constraints
  • Calculating migration expenses and anticipated savings
  • Ranking applications and data for migration priority based on business value and migration difficulty

The assessment phase provides essential groundwork for successful migration. Comprehensive evaluation clarifies the current IT environment and establishes a future vision for the cloud platform.

Mobilize

The mobilization phase focuses on assembling required resources, tools, and procedures for executing cloud migrations effectively. Following assessment completion, organizations prepare both personnel and technical infrastructure for migration. The mobilize phase encompasses:

  • Assembling a cloud team with roles including cloud architects and cloud developers
  • Creating a detailed migration plan specifying timelines, milestones, and deliverables
  • Configuring the cloud environment with appropriate security measures
  • Initiating pilot application migrations

Pilot applications enable testing of migration strategies and processes, confirming proper functionality before large-scale migration.

Migrate and modernize

This phase executes the actual migration of applications, workloads, and data. Activities include:

  • Applying insights from pilot migrations to scale application and workload migration
  • Refining application architecture to maximize cloud-native features and services
  • Evaluating performance, security, and expenses in the new cloud environment, implementing adjustments
  • Pursuing continuous advancement through adoption of emerging cloud technologies and capabilities

This phase continues indefinitely, as ongoing enhancement remains vital to cloud transformation. Post-migration optimization and innovation maximize cloud value realization.

What are the challenges in cloud migration?

Without adequate preparation, cloud migrations risk becoming protracted and expensive undertakings. Common obstacles include:

Technical complexity

Existing system complexities require identification and careful management. Interdependent applications may disrupt operations if migrated separately. Legacy systems frequently lack cloud compatibility and demand substantial refactoring or complete reconstruction.

Scalability challenges

Transferring numerous applications requires methodical, phased execution. Large data volume transfers consume considerable time when bandwidth limitations exist. Post-migration rollback to previous states may prove complex and time-intensive if complications arise. Interdependent migrations might temporarily require application downtime, disrupting business continuity.

Skills gap

Cloud platforms may be unfamiliar to teams experienced with conventional IT infrastructure. Staff may resist cloud adoption. Organizations must either train existing personnel or recruit cloud-skilled professionals. Beyond technical training, organizational culture frequently requires transformation to enable teams to embrace and effectively utilize new cloud tools and processes.

How can AWS support your cloud migration process?

Amazon Web Services (AWS), serving over one million active customers, brings extensive experience assisting organizations of all sizes in cloud workload migration. AWS supports both targeted lift-and-shift operations and comprehensive data center relocations. Organizations can select from multiple cloud migration tools designed to minimize risk and ensure reliable transitions:

  • AWS Application Discovery Service collects source server information supporting migration planning
  • AWS Application Migration Service delivers automated server rehosting to AWS infrastructure
  • AWS Database Migration Service (AWS DMS) enables rapid, secure database migration to AWS with source-to-target replication
  • AWS DataSync automates file and object data transfers between on-premises and AWS storage services
  • AWS Migration Acceleration Program (MAP) provides a comprehensive, proven migration program informed by experience migrating thousands of enterprise customers
  • Migration Evaluator supplies data-driven recommendations for appropriate sizing and cost optimization of computing resources

Source: AWS News Blog