Ubuntu 22.04 LTS – cron jobs do not run because cron service is inactive

📖 ~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

Scheduled scripts are skipped, causing backups and maintenance tasks to fail.

Environment & Reproduction

Appears after service disablement, package drift, or image hardening changes.

Root Cause Analysis

cron daemon is disabled or failing startup due to config issues.

Quick Triage

Check daemon status and inspect logs for parser or permission errors.

Step-by-Step Diagnosis

Validate crontab format and executable permissions for referenced scripts.

Solution – Primary Fix

Enable cron service and correct broken crontab entries.

Solution – Alternative Approaches

Migrate critical schedules to systemd timers for improved observability.

Verification & Acceptance Criteria

Test jobs execute at expected times and log output appears.

Rollback Plan

Revert recent crontab edits and restore prior scheduler definitions.

Prevention & Hardening

Use monitored wrapper scripts and centralized cron job version control.

Related Errors & Cross-Refs

Related to bad minute field and permission denied in cron execution.

Related tutorial: View the step-by-step tutorial for Ubuntu 22.04 LTS.

View all Ubuntu 22.04 LTS tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Ubuntu 22.04 cron service and scheduler best practices.