Ubuntu 14.04 LTS cron Jobs Stop Running After Permission Drift

📖 ~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

Backups and maintenance tasks do not run, creating operational risk.

Environment & Reproduction

Typically appears after manual edits to cron files or incorrect ownership.

Root Cause Analysis

Cron ignores files with unsafe permissions or invalid format entries.

Quick Triage

Check cron service status and recent syslog entries for parser errors.

Step-by-Step Diagnosis

Validate crontab syntax, file ownership, executable bits, and environment assumptions.

Solution – Primary Fix

Restore proper ownership/mode, reload cron, and run a controlled test job.

Solution – Alternative Approaches

Migrate critical jobs to systemd timers where supported by policy.

Verification & Acceptance Criteria

Expected jobs run on schedule and emit success logs over two cycles.

Rollback Plan

Reinstate previous crontab from version control backup if needed.

Prevention & Hardening

Use managed deployment for cron definitions with permission checks.

Related Errors & Cross-Refs

Related issues include PATH mismatches and shell interpreter assumptions.

Related tutorial: View the step-by-step tutorial for Ubuntu 14.04 LTS.

View all Ubuntu 14.04 LTS tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Consult cron man pages and Linux task scheduling operational docs.