Upgrading VMware Cloud Foundation (VCF) is a critical activity that requires careful planning and execution. Recently, during an upgrade from VCF 4.5 to 5.2, I encountered a unique and unexpected issue that tested my troubleshooting skills. This blog will delve into the problem, the steps taken to resolve it, and key lessons learned to help others avoid similar pitfalls.
Background
VMware Cloud Foundation 5.2 introduced significant enhancements, including improved scalability, enhanced automation features, and tighter integration with NSX and vSphere. The upgrade process itself, managed via SDDC Manager, is designed to be seamless. However, as with any complex system, unique issues can arise due to environmental factors, custom configurations, or unforeseen incompatibilities.
The Problem
During the upgrade of the Management Domain from VCF 4.5 to 5.2, the process stalled at the NSX-T upgrade phase. The specific error observed in the SDDC Manager logs was:
Task Failed: NSX Manager cluster is not reachable via API. Verify network connectivity and DNS resolution.
At first glance, the error suggested a simple connectivity issue. However, upon further investigation, it became apparent that all network connectivity checks and DNS resolutions were functioning as expected.
Root Cause Analysis
After diving deeper into the logs on the NSX Manager and consulting VMware’s KB articles, I discovered:
- Certificate Mismatch: During a prior maintenance activity, custom SSL certificates were manually updated on the NSX Manager cluster. However, these certificates were not propagated correctly across all nodes in the cluster, leading to inconsistencies.
- API Endpoint Failure: The mismatch caused intermittent failures in the NSX Manager cluster’s API endpoints, which only surfaced during the upgrade process when SDDC Manager attempted to orchestrate the upgrade.
- Time Drift: A slight NTP misconfiguration caused time drift between the SDDC Manager and the NSX Manager cluster, exacerbating the connectivity validation issue.
Resolution Steps
Here is how the issue was resolved:
- Certificate Re-Synchronization:
- Logged into the primary NSX Manager node and verified the certificate status using the following command:
get certificate
- Re-imported the correct SSL certificate and propagated it across all NSX Manager nodes using the NSX Manager UI.
- Logged into the primary NSX Manager node and verified the certificate status using the following command:
- NTP Configuration Fix:
- Ensured all nodes (SDDC Manager, NSX Manager, and vSphere components) were synchronized with the same NTP server.
- Validated time synchronization using:
ntpq -p
- Cluster Health Validation:
- Confirmed that all NSX Manager nodes were in a healthy state using:
get cluster status
- Confirmed that all NSX Manager nodes were in a healthy state using:
- Upgrade Retry:
- After resolving the certificate and time issues, restarted the upgrade process from SDDC Manager. This time, the NSX-T upgrade phase completed successfully.
Lessons Learned
- Pre-Upgrade Health Checks: Always perform thorough health checks on all components, including certificates, NTP synchronization, and cluster status, before starting an upgrade.
- Document Custom Changes: Maintain detailed documentation of any custom configurations, such as SSL certificate updates, and ensure these are validated post-maintenance.
- Monitor Logs: SDDC Manager and NSX Manager logs are invaluable for identifying and diagnosing issues. Familiarity with log locations and key error patterns can save hours of troubleshooting.
- Leverage VMware Resources: VMware’s Knowledge Base (KB) and support teams are excellent resources. In this case, consulting KB articles on NSX certificate management helped expedite the resolution.
Conclusion
The VCF upgrade process is robust, but unique environmental factors can lead to unexpected issues. By adopting a proactive approach to health checks, thorough documentation, and effective log analysis, you can minimize downtime and ensure a successful upgrade.
This experience reinforced the importance of preparation and attention to detail. If you’re planning a similar upgrade, consider these lessons to avoid potential pitfalls. Feel free to share your experiences or reach out with any questions!