RHEL 7 chronyd Not Syncing 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

Clock drift causes kerberos, TLS, and scheduled jobs to fail unpredictably.

Environment & Reproduction

chronyd service appears active on RHEL 7 but chronyc tracking shows unsynchronized status.

Root Cause Analysis

NTP upstream unreachable, firewalld blocks UDP 123, or incorrect source pool definitions prevent lock.

Quick Triage

Run chronyc sources -v, check firewalld rules, and inspect journalctl -u chronyd for offset warnings.

Step-by-Step Diagnosis

Validate ntp server DNS resolution, route symmetry, and stratum quality across configured peers.

Solution – Primary Fix

Update chrony.conf with reachable peers, open ntp service in firewalld, and restart chronyd with systemctl.

Solution – Alternative Approaches

Use internal enterprise time sources and isolate unreliable internet pools from critical servers.

Verification & Acceptance Criteria

chronyc tracking shows synchronized state and offset remains within operational tolerance.

Rollback Plan

Reapply previous chrony.conf and peer list if new sources cause worse drift or instability.

Prevention & Hardening

Monitor drift metrics and alert when sync is lost for more than a defined interval.

Related Errors & Cross-Refs

Related to authentication failures and yum TLS certificate date validation issues.

Related tutorial: View the step-by-step tutorial for rhel-7.

View all rhel-7 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Consult chrony and RHEL time synchronization documentation for robust enterprise deployments.