chronyd Not Syncing Time with NTP Sources

📖 ~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

Clock drift causes Kerberos failures, TLS validation issues, and inconsistent log/event timelines.

Environment & Reproduction

Following network changes, blocked UDP/123, VM suspend-resume cycles, or invalid NTP source configuration.

Root Cause Analysis

chronyd stopped, unreachable NTP servers, firewalld restriction, or stale `chrony.conf` entries.

Quick Triage

Run `systemctl status chronyd`, `chronyc tracking`, and check firewall policy for NTP egress.

Step-by-Step Diagnosis

Use `chronyc sources -v`, `journalctl -u chronyd –since -2h`, and `timedatectl status`.

Solution – Primary Fix

At least one source marked `^*` and low offset/jitter in `chronyc tracking` output.

Solution – Alternative Approaches

Correct NTP sources, allow network access, restart chronyd, and optionally run `chronyc makestep`.

Verification & Acceptance Criteria

Confirm stable synchronization over time and compare host time against trusted reference systems.

Rollback Plan

Restore prior `chrony.conf` from backup and restart service if new source list degrades stability.

Prevention & Hardening

Use redundant internal NTP servers, monitor drift thresholds, and enforce config management for chrony.

Related Errors & Cross-Refs

`systemctl enable –now chronyd && chronyc sources -v && chronyc tracking`

Related tutorial: View the step-by-step tutorial for rhel-8.

View all rhel-8 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

RHEL 8 time synchronization documentation and `man chronyc` for tracking and source diagnostics.