name: system-migration
description: Guides operating system and hardware platform migrations including Linux distribution changes, Windows to Linux migration, mainframe to x86 modernization, data center migrations (physical to virtual, P2V, V2V), hardware platform changes, system consolidation, and legacy system decommissioning. Covers OS compatibility, driver migration, system configuration transfer, and cutover procedures. Use when migrating operating systems, changing hardware platforms, moving from mainframes, or when users mention "OS migration", "Linux migration", "mainframe modernization", "P2V migration", "system upgrade", "data center migration", or "legacy system replacement".

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

1. Document current system state (OS version, kernel, packages, services, configurations)
2. Identify application and hardware compatibility requirements
3. Determine migration strategy (in-place upgrade vs fresh install)
4. Create detailed migration plan with timeline and resources

Phase 2: Preparation

1. Complete full system backups (OS, configurations, data)
2. Set up target system environment
3. Test migration procedures in non-production
4. Prepare rollback plan and validation criteria

Phase 3: Execution

1. Perform migration following tested procedure
2. Migrate configurations and customize for target system
3. Install and configure applications
4. Validate system functionality

Phase 4: Validation & Cutover

1. Run validation tests (See validation-and-testing.md)
2. Conduct parallel run period if applicable
3. Execute cutover to production
4. 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