Cloud migrations fail when critical steps are overlooked. A forgotten dependency, an untested failover, or a missed compliance requirement can derail projects and damage credibility.
This checklist consolidates lessons from hundreds of migrations into a practical reference. Use it to ensure your migration covers all the essential bases.
Phase 1: Discovery and Assessment
Before planning your migration, you need complete visibility into what you’re migrating.
Infrastructure Discovery
- Inventory all servers - Document every physical and virtual server including OS, CPU, memory, storage
- Map network topology - Document VLANs, subnets, firewalls, load balancers, DNS configurations
- Catalog storage systems - List all SAN, NAS, object storage with capacity and IOPS requirements
- Identify all databases - Document database engines, versions, sizes, replication configurations
- List middleware and runtime - Application servers, message queues, caching layers
- Document backup systems - Current backup tools, schedules, retention policies, recovery procedures
Application Discovery
- Create application inventory - Every application with owner, purpose, and business criticality
- Map application dependencies - Which applications depend on which databases, services, APIs
- Identify integration points - External APIs, data feeds, third-party services
- Document authentication flows - How users and services authenticate (LDAP, SSO, API keys)
- Catalog scheduled jobs - Cron jobs, batch processes, ETL jobs with schedules and dependencies
- Assess application architecture - Monolith vs microservices, stateful vs stateless, containerization readiness
Data Assessment
- Calculate data volumes - Total data size, growth rate, hot/warm/cold distribution
- Identify data sensitivity - PII, PHI, financial data, trade secrets requiring special handling
- Document data flows - How data moves between systems, applications, and external parties
- Assess data quality - Data integrity issues that might surface during migration
- Map data residency requirements - Geographic restrictions on data storage and processing
Compliance and Security Assessment
- List regulatory requirements - GDPR, HIPAA, PCI-DSS, SOC 2, industry-specific regulations
- Document security controls - Current firewall rules, encryption, access controls, audit logging
- Identify compliance certifications - Certifications you must maintain through migration
- Review vendor agreements - Cloud provider compliance certifications and shared responsibility model
- Assess security tooling - SIEM, IDS/IPS, vulnerability scanners, endpoint protection
Cost Analysis
- Calculate current costs - Hardware, software licenses, facilities, personnel, support contracts
- Estimate cloud costs - Use cloud provider calculators for target architecture
- Model migration costs - Data transfer, parallel running, professional services, training
- Project ongoing costs - Monthly cloud spend, reserved instances, support plans
- Build business case - ROI analysis comparing current state vs cloud target state
Phase 2: Planning
With discovery complete, build the migration plan.
Strategy Selection
- Assign 6Rs strategies - Categorize each application as Rehost, Replatform, Refactor, Repurchase, Retire, or Retain
- Prioritize applications - Order by business value, complexity, and dependencies
- Group into migration waves - Logical groupings that minimize risk and dependency issues
- Define success criteria - Measurable outcomes for each wave and overall migration
- Set realistic timelines - Account for testing, buffer time, and organizational constraints
Architecture Design
- Design target architecture - Network topology, compute resources, storage, databases
- Plan identity and access - IAM roles, service accounts, federation with existing identity providers
- Design networking - VPCs/VNets, subnets, security groups, routing, DNS
- Plan for high availability - Multi-AZ deployments, load balancing, failover configurations
- Design disaster recovery - Backup strategy, RTO/RPO requirements, cross-region replication
- Plan monitoring and observability - Metrics collection, logging, alerting, dashboards
For Kubernetes-based architectures, include cluster design, namespace strategy, and resource quotas in your planning.
Security Planning
- Design security architecture - Network segmentation, encryption at rest and in transit
- Plan secrets management - Vault, cloud-native secrets managers, rotation policies
- Define access controls - Least-privilege principles, break-glass procedures
- Plan security monitoring - SIEM integration, threat detection, incident response
- Document security runbooks - Response procedures for security events
Migration Tooling
- Select migration tools - AWS Application Migration Service, Azure Migrate, third-party tools
- Set up migration environment - Staging accounts, networks, credentials
- Configure replication - Server replication, database migration services
- Prepare data transfer - Network transfer capacity, offline transfer devices if needed
- Test migration tools - Validate tools work with your specific workloads
Team Preparation
- Assign roles and responsibilities - Migration lead, architects, engineers, testers, business contacts
- Plan training - Cloud platform training for operations teams
- Establish communication channels - Status updates, escalation paths, stakeholder communications
- Create runbooks - Step-by-step procedures for each migration wave
- Plan support coverage - Extended hours support during cutover periods
Phase 3: Preparation
Set up the target environment and validate readiness.
Cloud Environment Setup
- Create cloud accounts/subscriptions - Proper account structure for isolation and billing
- Configure billing and cost management - Budgets, alerts, tagging strategy
- Implement landing zone - Network, security, and governance foundations
- Set up identity federation - SSO integration with corporate identity provider
- Deploy core infrastructure - Networks, shared services, management tools
Network Preparation
- Configure connectivity - VPN or dedicated connection to cloud provider
- Set up DNS - Plan for DNS cutover, reduce TTLs before migration
- Configure firewall rules - Allow traffic between on-premise and cloud during migration
- Test connectivity - Verify latency and bandwidth meet requirements
- Plan IP addressing - Avoid conflicts between on-premise and cloud address spaces
Security Implementation
- Deploy security controls - Firewalls, WAF, DDoS protection
- Configure encryption - KMS keys, TLS certificates, encrypted storage
- Implement logging - CloudTrail/Activity Log, VPC flow logs, application logs
- Set up security monitoring - Cloud-native security services, SIEM integration
- Conduct security review - Validate architecture against security requirements
Testing Environment
- Create test/staging environment - Mirror production architecture at smaller scale
- Deploy test applications - Validate target architecture works
- Run load tests - Verify performance meets requirements
- Test failover scenarios - Validate HA and DR configurations work
- Test rollback procedures - Ensure you can revert if migration fails
Operational Readiness
- Set up monitoring - Dashboards for infrastructure and application metrics
- Configure alerting - Alerts for critical conditions with escalation paths
- Prepare incident response - Runbooks for common issues, on-call schedules
- Document operational procedures - Day-to-day operations in cloud environment
- Train operations team - Hands-on training with cloud management tools
Phase 4: Migration Execution
Execute the migration according to your plan.
Pre-Migration Checklist (Per Wave)
- Confirm wave scope - Applications, databases, and dependencies in this wave
- Verify prerequisites - Dependencies already migrated or accessible
- Notify stakeholders - Users, support teams, business owners aware of timeline
- Reduce DNS TTLs - Lower TTLs 24-48 hours before cutover
- Verify backups - Current backups exist and are tested for restore
- Confirm rollback plan - Documented procedure to revert if needed
Data Migration
- Start data replication - Begin copying data with sufficient lead time
- Monitor replication lag - Ensure data stays synchronized
- Validate data integrity - Row counts, checksums, spot checks
- Plan final sync window - Time needed for final data synchronization
- Test data access - Applications can read/write migrated data correctly
Application Migration
- Deploy application to target - Install and configure in cloud environment
- Configure connections - Update connection strings for cloud resources
- Test functionality - Validate all features work in new environment
- Performance test - Verify response times and throughput acceptable
- Security scan - Run vulnerability assessment on deployed application
For applications using CI/CD pipelines, update deployment configurations to target cloud environments.
Cutover Execution
- Execute cutover runbook - Follow documented steps precisely
- Stop application writes (if needed) - Quiesce applications for final sync
- Complete final data sync - Ensure all data is current
- Update DNS records - Point traffic to cloud environment
- Monitor closely - Watch for errors, performance issues, user reports
- Communicate completion - Notify stakeholders of successful cutover
Post-Cutover Validation
- Verify application functionality - All features working correctly
- Check data integrity - Data complete and accurate
- Validate integrations - External systems connecting properly
- Confirm monitoring - Alerts and dashboards showing expected data
- Test backup/restore - Backups running and restorable
- Document issues - Log any problems for post-migration review
Phase 5: Optimization
Migration is complete when optimized, not just when running.
Cost Optimization
- Right-size resources - Adjust instance sizes based on actual usage
- Implement auto-scaling - Scale resources based on demand
- Purchase reserved capacity - Commit to reserved instances for predictable workloads
- Review storage tiers - Move infrequently accessed data to cheaper storage
- Eliminate waste - Remove unused resources, orphaned volumes, old snapshots
- Set up cost monitoring - Dashboards and alerts for cost anomalies
Our AWS cost management services help organizations optimize cloud spending post-migration.
Performance Optimization
- Analyze performance metrics - Identify bottlenecks and optimization opportunities
- Tune database queries - Optimize slow queries, add appropriate indexes
- Configure caching - Implement caching layers where beneficial
- Optimize networking - Review and tune network configurations
- Load test at scale - Verify performance under peak load conditions
Security Hardening
- Review access permissions - Remove excessive privileges granted during migration
- Enable additional security features - Advanced threat protection, encryption options
- Conduct penetration testing - Identify vulnerabilities in cloud deployment
- Review compliance posture - Verify compliance requirements still met
- Update security documentation - Reflect current security architecture
Operational Excellence
- Automate routine tasks - Infrastructure provisioning, patching, backups
- Implement infrastructure as code - Terraform or native IaC for reproducibility
- Refine monitoring and alerting - Reduce noise, catch real issues
- Document lessons learned - Capture insights for future migrations
- Train remaining team members - Ensure full team competency
Phase 6: Decommissioning
Clean up the old environment after successful migration.
Pre-Decommissioning
- Confirm migration success - All applications stable in cloud for defined period (30-90 days typical)
- Verify no dependencies remain - No systems still pointing to old environment
- Archive necessary data - Retain data required for compliance or reference
- Document old configurations - In case reference needed later
Decommissioning Execution
- Terminate connections - VPNs, dedicated connections to old environment
- Power down servers - Shut down but retain for recovery period
- Cancel licenses - End software subscriptions no longer needed
- Terminate leases/contracts - Data center, colocation, managed services
- Dispose of hardware - Secure disposal with data destruction verification
Final Cleanup
- Remove DNS records - Clean up old DNS entries
- Revoke credentials - Disable accounts and API keys for old systems
- Update documentation - Remove references to decommissioned systems
- Celebrate success - Recognize team efforts and achievements
Quick Reference by Migration Type
Rehost Migration Checklist
For lift-and-shift migrations, focus on:
- Server inventory with exact specifications
- Network configuration documentation
- Replication tool setup and testing
- Cutover window planning
- Post-migration monitoring setup
Database Migration Checklist
For database migrations specifically:
- Schema compatibility verification
- Data type mapping documentation
- Stored procedure and function migration
- Index and constraint recreation
- Replication configuration and testing
- Performance baseline comparison
- Connection string updates for all applications
Kubernetes Migration Checklist
For Kubernetes workloads:
- Cluster architecture design
- Container image registry setup
- Kubernetes manifest adaptation for target platform
- Ingress controller configuration
- Storage class mapping
- Service mesh consideration
- GitOps deployment pipeline setup
Common Mistakes to Avoid
Planning Phase
- Incomplete discovery - Missing applications or dependencies surface during migration
- Optimistic timelines - Underestimating testing and buffer time
- Insufficient stakeholder buy-in - Resistance during execution
Execution Phase
- Skipping testing - Production issues that testing would have caught
- Poor communication - Stakeholders surprised by outages or changes
- Inadequate monitoring - Problems not detected until users report them
Post-Migration
- Declaring victory too early - Decommissioning before stability proven
- Skipping optimization - Running expensive, inefficient configurations
- Neglecting documentation - Institutional knowledge lost
Summary
Cloud migration success comes from thorough preparation and disciplined execution. This checklist covers the critical items, but every migration has unique requirements. Adapt the checklist to your specific situation, and do not skip steps because they seem obvious.
The organizations that execute smooth migrations are those that invest in discovery, test thoroughly, communicate constantly, and optimize continuously after migration.
Need Help with Your Cloud Migration?
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