Server Migration Checklist 2025

Overview and scope

This document is a practical cloud migration plan. It explains who does what, what moves, how to test, and how to recover if something fails. It focuses on moving applications, data, and networking to a new cloud or cloud region with clear steps and responsibilities.

Define scope early. Say which applications, databases, and services will move. State the migration window and expected downtime. List environments included (dev, test, prod) and any systems that will stay on-premises.

Define success criteria. Examples: minimal user impact, meeting RTO/RPO targets, passing functional and performance tests, and getting stakeholder sign-off.

Roles, stakeholders, and communication plan

Assign clear roles so no task is missed.

• Executive sponsor: approves budget and final go/no-go.
• Project manager: coordinates tasks, schedule, and reporting.
• Cloud architect: designs target architecture and migration approach.
• App owners: validate functionality and accept post-migration tests.
• DBAs: lead data migration, backups, and integrity checks.
• Network and security engineers: configure routing, firewalls, and IAM.
• Operations/Run team: run cutover, monitoring, and rollback.
• QA/test team: design and run migration tests.
• Support staff: handle incident triage after cutover.

Communication plan basics:

• Daily stand-ups during migration weeks.
• Status cadence: hourly during cutover, twice-daily in validation phase.
• Escalation path: who to call for blocking issues, with phone numbers.
• Single source of truth: a collaboration space (ticketing tool, shared doc) for logs, decisions, and runbooks.

Inventory and dependency mapping

Inventory everything. A complete inventory avoids surprises.

Collect these items for each asset:

• Application name, owner, and business priority.
• Host or VM details: CPU, RAM, disk, OS, patches.
• Database type, size, and replication setup.
• Network components: IPs, subnets, VIPs, load balancers.
• Storage: volumes, IOPS, encryption.
• Third-party integrations and APIs.
• Scheduled jobs, cron tasks, and batch windows.
• Compliance tags and data sensitivity level.

Map dependencies visually. Use a simple diagram showing:

• Upstream services each app relies on.
• Downstream clients that depend on the app.
• Shared resources (databases, caches, message queues).

Dependency mapping helps sequence migrations and avoid breaking shared services.

Risk assessment and compliance requirements

List risks and assign likelihood and impact. Keep it simple and actionable.

Common risks:

• Data loss during transfer (mitigate with snapshots and validation).
• Prolonged downtime from failed cutover (mitigate with dry runs and fallback).
• Security misconfiguration exposing data (mitigate with security reviews and audits).
• Third-party incompatibility (mitigate with vendor checks and test environments).

Compliance checklist:

• Identify applicable regulations (GDPR, HIPAA, PCI, SOC2).
• Note data residency and encryption rules.
• Ensure logging and audit trails meet standards.
• Map required certifications or attestations for the target cloud.

Document risk owners and mitigation steps, and require sign-off for high-risk items before cutover.

Backup, snapshot, and recovery strategy

Backups are your safety net. Define recovery objectives first.

• RTO (Recovery Time Objective): how long services can be down.
• RPO (Recovery Point Objective): maximum acceptable data loss.

Design a backup plan:

• Full and incremental backups for databases.
• File system snapshots for critical servers.
• Export of configuration and infrastructure as code (IaC) templates.
• Offsite or cross-region copies of backups.

Test recovery procedures:

• Restore a database from backup and validate.
• Rebuild a test server from snapshot and confirm configs.
• Verify restoration times meet RTO targets.

Use multiple recovery paths: live replication for minimal RPO, periodic backups for archival, and immutable storage for ransomware protection.

Migration strategy and target architecture

Choose a migration approach for each workload:

• Rehost (“lift and shift”): move VMs as-is. Fast but may not optimize cost.
• Replatform: make small changes to use cloud services (e.g., managed database).
• Refactor: redesign app to cloud-native services. Best for long-term benefit but longer timeline.
• Replace: adopt SaaS alternatives where appropriate.

Define the target architecture:

• Regions and availability zones used.
• Network layout: VPCs, subnets, routing, and peering.
• Security posture: IAM roles, least privilege, and key management.
• Data flows: where data is stored and replicated.
• Observability: logging, metrics, and tracing architecture.

Match migration method to each app based on business priority, complexity, and budget.

Pre-migration testing and validation

Test well before cutover. Testing reduces surprises.

Types of tests:

• Unit and integration tests for application logic.
• Full application functional testing in a staging cloud environment.
• Load and stress tests that replicate expected peak traffic.
• Failover tests for replicated databases and multi-AZ setups.
• Security scans and vulnerability assessments.

Validation checklist:

• Configuration parity between staging and production target.
• Data integrity checks after test migrations.
• End-to-end user journeys pass with acceptable performance.
• Monitoring and alerting triggers work.

Record results and make fixes before moving to production.

Cutover plan and downtime minimization

Plan cutover like a script. Include exact steps and timing.

Steps to minimize downtime:

• Use phased migration: move non-critical services first.
• Employ database replication with cutover switch to reduce RPO.
• Freeze non-essential writes before final sync.
• Use DNS TTL reduction days before cutover to speed DNS propagation.
• Run parallel environments and switch traffic via load balancer or DNS.

Sample cutover outline:

1. Final backup and pre-checks.
2. Stop writes or enter maintenance mode.
3. Perform final data sync.
4. Update DNS or load balancer to target endpoints.
5. Smoke tests and quick functional checks.
6. Open service and monitor closely.

Define exact time windows and expected downtime at each step. Communicate them to users.

DNS, networking, and security configuration

Networking and DNS are critical points of failure. Plan carefully.

DNS:

• Lower TTLs 48-72 hours before cutover.
• Prepare DNS records and validations in target DNS provider.
• Have a rollback DNS plan and keep old DNS zone active until validation complete.

Networking:

• Pre-allocate IPs, subnets, and route tables.
• Test VPN or direct connect links before migration.
• Ensure MTU and firewall rules match requirements.
• Validate cross-region replication and latency.

Security:

• Apply least privilege IAM roles and service accounts.
• Encrypt data in transit and at rest.
• Rotate keys and verify secrets are in secure stores.
• Run penetration tests or security scans pre- and post-migration.

Record all changes and get security sign-off before accepting production traffic.

Post-migration verification and performance tuning

Verify everything after cutover and tune for performance.

Verification steps:

• Confirm all services are reachable and responding.
• Run full application functional tests and user acceptance tests.
• Validate data integrity with checksums and record counts.
• Check logs and monitoring for anomalies.

Performance tuning:

• Adjust instance sizes and auto-scaling thresholds.
• Optimize database indexes and query plans if latency increased.
• Tune caching layers and CDN usage for static assets.
• Monitor costs and right-size reserved instances or savings plans.

Keep a short stabilization period (usually 24–72 hours) for intensive monitoring and quick fixes.

Rollback and contingency procedures

Prepare clear rollback procedures before starting.

Define rollback triggers:

• Critical service unavailable beyond agreed downtime.
• Data corruption detected during validation.
• Security breach or major misconfiguration.

Rollback steps should be as simple as possible:

• Repoint DNS or load balancer to old environment.
• Restore database from snapshots if needed.
• Re-enable writes to source systems.

Test rollback in a dry run. Ensure backups and logs needed for rollback are available and accessible.

Documentation, handover, and post-migration review

Document everything. Good documentation prevents repeated problems.

Deliverables for handover:

• Final inventory and architecture diagrams.
• Updated runbooks for operations and on-call staff.
• Backup and recovery procedures with tested steps.
• Security configuration and audit logs.
• Cost and usage reports.

Conduct a post-migration review:

• Capture what went well and what failed.
• Record root causes for issues and corrective actions.
• Update migration runbooks and training for teams.

Hold a lessons-learned session and assign owners to fix remaining gaps. Close the project only after action items are completed or scheduled.

This plan gives a complete, practical path to move services to the cloud with clear roles, tests, recovery plans, and post-migration checks. Use it as a checklist and adapt details to your environment, compliance needs, and business priorities.