CentOS Stream 10 – Common Problem 231 – 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

chronyd logs significant offset values and the clock fails to converge with upstream NTP servers.

Environment & Reproduction

Common after long downtime, virtualization snapshots, or firewall blocks on UDP 123.

Root Cause Analysis

chronyd will not step the clock once it has slewed past the configured makestep threshold.

Quick Triage

Check chronyc tracking, sources, and sourcestats to confirm reachability and dispersion.

Step-by-Step Diagnosis

Run: chronyc tracking; chronyc sources -v; ss -unap | grep 123.

Solution – Primary Fix

Edit /etc/chrony.conf to set makestep 1 -1 during recovery and run chronyc makestep.

Solution – Alternative Approaches

Use a closer pool or local stratum-1 source, and ensure firewall permits NTP egress.

Verification & Acceptance Criteria

chronyc tracking shows offset within milliseconds and System time line is in sync.

Rollback Plan

Restore original makestep value and chrony.conf from backup after the clock has stabilised.

Prevention & Hardening

Monitor offset with chronyc tracking and alert when it exceeds organisational thresholds.

Related Errors & Cross-Refs

Related to kernel clocksource issues and virtualization host time drift.

Related tutorial: View the step-by-step tutorial for centos-stream-10.

View all centos-stream-10 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

chrony.conf(5) and chronyc(1) documentation.