Windows Server 2022 administrators have been grappling with critical NUMA-related startup failures, but Microsoft has released essential updates (KB5050117 and KB5052819) to address these issues. This guide explores the root causes, solutions, and best practices for maintaining system stability.

Understanding NUMA Startup Failures in Windows Server 2022

Non-Uniform Memory Access (NUMA) architecture is crucial for optimizing performance in multi-processor systems. However, Windows Server 2022 has experienced critical failures where systems:

  • Fail to boot properly
  • Experience memory allocation errors
  • Show degraded performance on NUMA-aware applications
  • Generate Event ID 37 errors in system logs

Microsoft confirmed these issues primarily affect systems with:
- 64 or more logical processors
- Complex NUMA node configurations
- Certain hypervisor configurations

The Fixes: KB5050117 and KB5052819 Explained

Microsoft addressed these problems through two critical updates:

KB5050117 (August 2023 Update)

  • Resolved memory management unit (MMU) initialization failures
  • Fixed NUMA node detection during boot sequence
  • Improved handling of large memory configurations

KB5052819 (September 2023 Update)

  • Enhanced NUMA balancing algorithms
  • Fixed race conditions in processor group initialization
  • Added additional error handling for startup scenarios

Step-by-Step Resolution Guide

  1. Verify Your System is Affected
    - Check System Logs for Event ID 37
    - Review processor configuration in Task Manager
    - Run Get-NumaNode in PowerShell

  2. Install the Updates
    ```powershell
    # For standalone servers:
    Install-WindowsUpdate -KBNumber KB5050117
    Install-WindowsUpdate -KBNumber KB5052819

# For WSUS environments:
Approve the updates in your WSUS console
```

  1. Post-Update Configuration
    - Reboot the server twice (required for NUMA reinitialization)
    - Verify NUMA configuration with:
    powershell Get-WinEvent -LogName System | Where-Object {$_.Id -eq 37} Get-CimInstance Win32_ComputerSystem | Select-Object NumberOfLogicalProcessors

Best Practices for NUMA Configuration

  • Memory Allocation: Ensure balanced memory distribution across NUMA nodes
  • Processor Affinity: Configure applications with NUMA awareness
  • Monitoring: Implement regular checks for NUMA-related events
  • Update Strategy: Always test NUMA-related updates in staging first

When to Contact Microsoft Support

If issues persist after applying both updates:
1. Collect full memory dumps during boot failures
2. Gather processor topology information
3. Document exact error messages and timing

Microsoft's support team has specialized tools for diagnosing complex NUMA issues in Windows Server 2022 environments.

Future Considerations

With increasing core counts in modern servers, NUMA architecture will become even more critical. Microsoft has committed to:
- Quarterly NUMA-specific updates
- Enhanced diagnostic tools in Windows Admin Center
- Improved documentation for large-scale deployments

Administrators should subscribe to Microsoft's NUMA-related advisories and plan regular maintenance windows for NUMA-specific updates.