FreeBSD 14 – Cron Jobs Stop Running Due to Syntax Errors – Scheduler Recovery

📖 ~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 jobs silently stop, causing missed backups and maintenance tasks.

Environment & Reproduction

Often follows manual crontab edits with malformed schedule expressions.

crontab -l
service cron status

Root Cause Analysis

Parser rejects invalid cron entries, preventing intended commands from executing.

Quick Triage

Check cron logs and verify crontab syntax line by line.

tail -n 120 /var/log/cron
crontab -l | nl -ba

Step-by-Step Diagnosis

Validate environment assumptions, script paths, and shell compatibility.

env -i /bin/sh -c ''
which 

Solution – Primary Fix

Correct schedule syntax, use absolute paths, and reload cron context.

crontab -e
service cron restart

Solution – Alternative Approaches

Migrate critical jobs to supervised task runners with explicit logging.

Verification & Acceptance Criteria

Test jobs execute at expected times and emit success logs.

echo '* * * * * /usr/bin/date >> /tmp/cron_test.log' | crontab -
sleep 70; tail -n 2 /tmp/cron_test.log

Rollback Plan

Restore known-good crontab backup if revised schedule breaks job cadence.

Prevention & Hardening

Lint crontab updates in CI and require dry-run validation for critical jobs.

Related Errors & Cross-Refs

bad minute, malformed crontab entry, command not found in cron context.

Related tutorial: View the step-by-step tutorial for freebsd-14.

View all freebsd-14 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

FreeBSD cron manual and scheduling reliability guidance.