RHEL 9: chronyd Not Synchronizing System Time

📖 ~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, causing certificate and authentication issues across services.

Environment & Reproduction

Run `timedatectl` and `chronyc tracking` to confirm NTP synchronization status.

Root Cause Analysis

Verify chrony installation using `dnf list installed chrony`.

Quick Triage

Check `systemctl status chronyd` and confirm service is enabled.

Step-by-Step Diagnosis

Review daemon activity and source reachability with `journalctl -u chronyd -b`.

Solution – Primary Fix

Correct `/etc/chrony.conf`, then run `systemctl restart chronyd` and `chronyc makestep`.

Solution – Alternative Approaches

Allow NTP where needed using `firewall-cmd –add-service=ntp –permanent` and reload.

Verification & Acceptance Criteria

SELinux defaults typically permit chronyd; investigate only if custom confinement exists.

Rollback Plan

Check sync state after reboot to ensure stable time source selection.

Prevention & Hardening

Use multiple trusted NTP sources and monitor stratum and offset metrics.

Related Errors & Cross-Refs

Restore prior `chrony.conf` from backup if custom source changes cause instability.

Related tutorial: View the step-by-step tutorial for rhel-9.

View all rhel-9 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Consult `man chrony.conf` and `chronyc` command documentation.