Ubuntu 20.04 LTS – Common Problem 022 – 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

Time repeatedly jumps or never stabilizes because multiple sync daemons compete.

Environment & Reproduction

Ubuntu 20.04 where chrony and systemd-timesyncd are both installed and partially enabled.

Root Cause Analysis

Conflicting NTP clients adjust the clock independently, causing drift and jitter artifacts.

Quick Triage

Run ‘timedatectl status’ and ‘systemctl status systemd-timesyncd chrony’ to detect dual-active state.

Step-by-Step Diagnosis

Inspect service enablement, verify selected source peers, and compare sync statistics over time.

Solution – Primary Fix

Choose one service, disable the other, and restart the chosen daemon with validated NTP sources.

Solution – Alternative Approaches

Use chrony on latency-variable systems while keeping timesyncd for simpler minimal hosts.

Verification & Acceptance Criteria

Single NTP client active, clock offset stable, and no synchronization flapping.

Rollback Plan

Re-enable previous time daemon if selected service fails policy or compatibility checks.

Prevention & Hardening

Enforce time-service standard in provisioning templates and audit service state regularly.

Related Errors & Cross-Refs

NTP synchronized: no, offset spikes, and certificate validity anomalies.

Related tutorial: View the step-by-step tutorial for Ubuntu 20.04 LTS.

View all Ubuntu 20.04 LTS tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

chrony docs, systemd-timesyncd manual, and Ubuntu time synchronization operations.