System Migration
Overview
Provides comprehensive guidance for system-level migrations including operating system changes, hardware platform transitions, mainframe modernization, virtualization, and data center migrations. Focuses on system infrastructure that underlies applications and platforms.
Key Points:
- System migrations often involve multiple skills: OS + database + application coordination
- Plan for 30-50% more time than initial estimates
- Parallel run periods reduce risk but increase cost
- Mainframe migrations are typically multi-year projects
- Physical to virtual conversions rarely have issues with modern hardware
- Always validate hardware compatibility before OS migrations
Workflow Decision Tree
Choose your migration path based on the system type:
1. Operating System Migration
Use for: Linux distribution changes, Windows to Linux, OS version upgrades Load: migration-types.md for detailed workflows
2. Hardware Platform Migration
Use for: Mainframe to x86, architecture changes, system consolidation Load: migration-types.md for platform-specific guidance
3. Virtualization Migration
Use for: Physical to Virtual (P2V), Virtual to Virtual (V2V), cloud migrations Load: migration-types.md for virtualization patterns
4. Data Center Migration
Use for: Facility moves, infrastructure consolidation, hybrid cloud Load: migration-types.md for data center procedures
Standard Migration Workflow
Phase 1: Assessment & Planning
- Document current system state (OS version, kernel, packages, services, configurations)
- Identify application and hardware compatibility requirements
- Determine migration strategy (in-place upgrade vs fresh install)
- Create detailed migration plan with timeline and resources
Phase 2: Preparation
- Complete full system backups (OS, configurations, data)
- Set up target system environment
- Test migration procedures in non-production
- Prepare rollback plan and validation criteria
Phase 3: Execution
- Perform migration following tested procedure
- Migrate configurations and customize for target system
- Install and configure applications
- Validate system functionality
Phase 4: Validation & Cutover
- Run validation tests (See validation-and-testing.md)
- Conduct parallel run period if applicable
- Execute cutover to production
- Monitor closely post-migration
Core Best Practices
✅ Thorough Testing - Test everything in non-production environments first ✅ Complete Backups - Multiple backups at different stages before migration ✅ Automation - Script repeatable tasks to reduce errors and ensure consistency ✅ Gradual Migration - Migrate in phases, not all at once ✅ Rollback Plan - Always have a tested way to revert changes ✅ Documentation - Document every configuration, decision, issue, and resolution
Reference Files
Load these reference files based on specific migration needs:
- Migration Types: See migration-types.md when:
- Planning OS migrations (Linux distro changes, Windows to Linux) - Executing hardware platform migrations (mainframe to x86) - Performing virtualization migrations (P2V, V2V) - Conducting data center migrations
- System Configuration Migration: See system-configuration-migration.md when:
- Migrating network configurations - Transferring user accounts and permissions - Moving system services and cron jobs - Replicating firewall and security settings
- Validation and Testing: See validation-and-testing.md when:
- Designing test plans for migrations - Validating system functionality post-migration - Conducting performance benchmarking - Testing disaster recovery procedures
- Rollback Procedures: See rollback-procedures.md when:
- Planning rollback strategies - Migration fails or encounters critical issues - Need to revert to original system state
- Tools and Resources: See tools-and-resources.md when:
- Selecting migration tools (rsync, dd, clonezilla, etc.) - Choosing automation frameworks - Need monitoring and validation utilities
- Best Practices: See best-practices.md when:
- Need comprehensive checklist for migration execution - Planning communication and stakeholder management - Establishing monitoring and alerting strategies
- Anti-Patterns: See anti-patterns.md when:
- Need to avoid common migration mistakes - Reviewing migration plans for potential issues - Troubleshooting failed or problematic migrations