CentOS Stream 9 – Common Problem 111 – Diagnosis and Fix

📖 ~1 min read

Table of contents

1. Symptom & Impact
2. Environment & Reproduction
3. Root Cause Analysis
4. Quick Triage
5. Step-by-Step Diagnosis
6. Solution – Primary Fix
7. Solution – Alternative Approaches
8. Verification & Acceptance Criteria
9. Rollback Plan
10. Prevention & Hardening
11. Related Errors & Cross-Refs
12. References & Further Reading

Symptom & Impact

System clock drifts; Kerberos and TLS validation start to fail.

Environment & Reproduction

Default chrony.conf points to pool servers that may be unreachable.

Root Cause Analysis

Firewalled NTP traffic or stratum-1 misconfiguration causes drift.

Quick Triage

chronyc tracking and sources -v summarize sync state.

Step-by-Step Diagnosis

Inspect /etc/chrony.conf for pool/server lines and ‘makestep’.

Solution – Primary Fix

Configure reachable internal NTP servers and restart chronyd.

Solution – Alternative Approaches

Use chronyc burst to force initial sync after long downtime.

Verification & Acceptance Criteria

chronyc tracking shows Leap Status: Normal and small offset.

Rollback Plan

Re-enable previous chrony.conf via backup and restart the service.

Prevention & Hardening

Monitor offset with node_exporter and alert above 100ms.

Related Errors & Cross-Refs

Related: VM clock source mismatch and PTP coexistence issues.

Related tutorial: View the step-by-step tutorial for centos-stream-9.

View all centos-stream-9 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

chrony documentation and Red Hat time-sync guide.