Data center migration is not just about moving servers from one location to another. It is an infrastructure project that directly affects service availability, data security, system performance, and business operating costs.
In 2025–2026, companies initiate data center migration for various reasons: growing workloads, outdated infrastructure, the need to improve fault tolerance, regulatory requirements, or plans for scaling. A mistake at any stage can lead to downtime, data loss, and financial losses.
Types of Data Center Migration
Before starting the project, it is important to determine which type of migration the business needs. There is no universal scenario — the choice depends on the current infrastructure, objectives, and constraints.
Full and Partial Migration
Full migration involves moving the entire infrastructure to a new environment, followed by decommissioning the existing data center. This approach is used when closing a site, changing a provider, or performing a complete architectural redesign.
Partial migration is applied when:
- only selected systems or services are migrated;
- a hybrid model is introduced;
- part of the workloads remains on-premise due to security or regulatory requirements.
Common Migration Scenarios
In practice, the following scenarios are most common:
- On-premise → on-premise
Migration to another physical data center. Relevant when changing location, provider, or reliability level. - On-premise → colocation
The company retains control over its hardware while placing it in a professional data center with SLA, redundancy, and physical security. - On-premise → cloud
Migration to a public or private cloud. Suitable for scalable workloads that are less dependent on physical hardware. - Hybrid model
A combination of approaches where some systems remain on-premise while others are moved to the cloud or colocation.
Workload Migration Approaches
The migration type is also defined by how systems are transferred:
- Lift-and-shift — migration “as is,” without architectural changes.
Fast to implement, but it does not address the limitations of legacy solutions. - Re-platforming — partial adaptation to the new environment, such as changing storage or virtualization platforms.
A compromise between speed and optimization. - Re-architecting — redesigning the architecture to meet new requirements.
The most complex approach, but strategically the most effective.
Choosing the right migration scenario is the foundation of the entire project. Mistakes at this stage lead to increased timelines, higher costs, and growing technical debt after go-live.
Migration Goals, KPIs, and Constraints
Data center migration should start not with infrastructure, but with business objectives. Without this, the project easily turns into an uncontrolled system transfer with no clear outcome.
Defining Objectives
In practice, migration goals are most often related to improving service availability, reducing operating costs, increasing performance, meeting security and compliance requirements, and preparing infrastructure for scaling. It is important to clearly identify the primary objective, as trade-offs between these goals are common.
Migration KPIs
To evaluate project success, measurable indicators are defined in advance:
- acceptable downtime levels;
- target SLA values;
- post-migration performance metrics;
- changes in total cost of ownership (TCO);
- compliance with backup and recovery requirements.
These KPIs are used as decision-making criteria throughout all stages of the migration.
Project Constraints
In addition to objectives, constraints must be explicitly defined:
- maximum allowable service downtime;
- strict deadlines;
- project budget;
- regulatory or customer requirements;
- dependencies on external vendors.
Special attention should be given to ownership — who makes final decisions and who is responsible for the outcome. Without clear ownership, migration becomes difficult to manage.
Audit of the Current Infrastructure
The audit is a key stage that determines the complexity and risks of the entire migration. Its purpose is to obtain a complete view of the current state of the infrastructure.
Infrastructure Layer
At this stage, the following are documented: servers and their configurations, storage systems, network architecture and points of failure, virtualization platforms, and management tools. It is important to understand not only the composition of the infrastructure, but also its utilization levels.
A common mistake is to view applications in isolation. During the audit, the following are identified:
- dependencies between services;
- external integrations;
- outdated or rarely used systems.
This helps avoid situations where migrating one service causes a chain of related components to stop working.
Data and Service Criticality
For each service, the following are defined: data types, volumes, availability requirements, acceptable data loss (RPO), and recovery time objectives (RTO). The outcome of this stage is a current-state map that includes:
- a list of all systems;
- their interdependencies;
- business criticality;
- identified risks and single points of failure.
Without this document, further migration planning becomes an assumption rather than a controlled process.
Workload Classification and Prioritization
After completing the infrastructure audit, the next step is to determine how and in what order systems should be migrated. For this purpose, workloads are classified based on several key parameters.
Business Criticality
First, the impact of services on business processes is assessed. Systems whose downtime directly affects business operations require a dedicated migration scenario and minimal downtime. Less critical services allow for more flexible migration windows and are often used to validate migration processes.
This classification makes it possible to define in advance availability requirements, acceptable migration windows, and the required level of fault tolerance after migration.
Technical Characteristics of Workloads
The next criterion is the nature of the applications themselves. Stateless services are generally easier and faster to migrate. Stateful systems, including databases and queues, require careful synchronization and additional testing.
At this stage, the following factors are also considered:
- sensitivity to latency;
- network bandwidth requirements;
- dependencies on external services.
Legacy Systems and Technical Debt
Outdated solutions and systems with a high level of technical debt are analyzed separately. Migrating them without changes often preserves existing issues in the new environment. In some cases, it is more reasonable to consider modernization or a phased decommissioning of such systems.
Migration Order
Based on the classification, the migration priority is defined as follows:
- test and non-critical systems;
- supporting business services;
- core mission-critical workloads.
This approach reduces risks and allows migration complexity to increase gradually.
Target Architecture Design
The target architecture defines what the infrastructure should look like after the migration is completed. It serves as the primary reference point for technical decisions and change control.
Deployment Model Selection
At this stage, the format of the target environment is defined:
- physical data center;
- colocation;
- cloud or hybrid model.
The choice depends on security requirements, scalability, and the level of infrastructure control, as well as the company’s long-term business plans.
Network Architecture and Fault Tolerance
The network structure is designed, including segmentation, redundancy, and failure scenarios. Particular attention is paid to connectivity between components and the ability to restore services in the event of outages. Errors at this stage are difficult to correct after go-live, which is why the architecture must be carefully planned in advance.
Security and Data Protection
Within the target architecture, access models and privilege separation are defined, along with data encryption requirements, logging and monitoring approaches, and backup and recovery policies.
Target Architecture Document
The outcome of this stage is the Target Architecture document, which describes:
- the target infrastructure;
- key architectural decisions;
- constraints and assumptions.
This document is used as the foundation for implementing the migration and for ensuring that the final result aligns with the original plan.
Migration Plan
The migration plan turns architectural decisions into a manageable project. Its purpose is to define the sequence of actions, minimize downtime, and document response scenarios for failures.
Phases and Migration Waves
Migration is rarely performed in a single step. Infrastructure is moved in stages, using migration waves, each of which includes a group of related systems. This approach allows risks to be controlled and the process to be adjusted as the project progresses.
Typically, the plan includes:
- a preparation phase;
- several migration waves;
- final cutover and stabilization.
Different migration scenarios are selected for different systems. Non-critical services can be stopped during migration, while key workloads require minimal or zero downtime. This is achieved through data replication, temporary parallel operation, and phased traffic switching.
Rollback Strategy
Each migration stage must have a rollback scenario. The rollback plan describes how to return a system to its original state in case of errors or performance degradation. The absence of such a plan is one of the most common causes of prolonged downtime.
It is also important to define in advance who is informed about migration progress and at what stages. Business stakeholders, support teams, and technical teams must understand when service changes may occur and how to respond to incidents.
Target Environment Preparation
Before system migration begins, the target environment must be fully prepared to handle workloads. Errors at this stage will inevitably surface during the migration process.
In the new environment, compute resources, storage systems, and a virtualization or orchestration platform are deployed. All components must comply with the requirements defined in the target architecture.
Network and Connectivity
Network connections are configured separately:
- internal routing;
- VPN or dedicated links;
- firewalls and network segmentation.
Network connectivity between the source and target environments must be stable and thoroughly tested before migration starts.
Monitoring, Backup, and Test Environment
Before migrating production systems, monitoring and logging are configured, along with backup mechanisms in the target environment. This allows service health to be monitored from the first minutes of operation. In addition, a test environment is created to validate migration and rollback scenarios.
Data and Application Migration
Data and application transfer is the most sensitive stage of a data center migration. This is where issues most often arise that affect timelines and service stability.
Data Migration
The data transfer method is selected based on data volume, criticality, and downtime requirements. For smaller volumes, a one-time transfer may be sufficient, while large datasets require staged synchronization and incremental copies.
During migration, it is important to ensure:
- data integrity;
- version control and data consistency;
- minimization of data loss during cutover.
Special attention is paid to migration windows and network load to ensure that data transfer does not impact production systems.
Application Migration
Applications are migrated according to a predefined order, taking dependencies into account. After each service is migrated, a basic functionality check is performed before proceeding to the next component. When working with legacy applications, additional environment configuration or temporary parallel operation of the old and new environments is often required.
Testing and Cutover
After systems are migrated, it is critical to confirm that the infrastructure is ready for production use.
Testing is conducted in several stages and includes:
- service functionality validation;
- performance and load testing;
- failure and recovery scenario testing.
The goal of this phase is to identify issues before they affect users.
Cutover represents the point of final transition to the new infrastructure. It is performed according to a pre-approved plan and is accompanied by enhanced monitoring. In the first hours and days after cutover, the team must be prepared to respond quickly to incidents and metric deviations.
Post-Migration and Optimization
Data center migration does not end at the moment of switching to the new infrastructure. After go-live, a stabilization and optimization phase begins, which directly impacts the long-term outcome of the project.
In the first weeks, key availability and performance metrics are analyzed. At this stage, bottlenecks that did not appear in the test environment are often identified. In parallel, resource usage is optimized, helping reduce operating costs and improve infrastructure efficiency.
Special attention is given to backup and recovery scenarios. After migration, it is important to ensure that backup and disaster recovery operate in the new environment in accordance with defined RPO and RTO targets.
Once stabilization is complete, technical documentation is updated, architectural changes are documented, and operational procedures are finalized. Only after this can the legacy infrastructure be decommissioned or used as a backup site.
The project is considered complete when the new environment is not only stable, but also aligned with the original business objectives of the migration.
