📖 ~1 min read
Table of contents
Symptom & Impact
A required service fails at startup, causing application outage or degraded host functionality.
Environment & Reproduction
Ubuntu 18.04 using systemd units for web, database, or custom app daemons.
Root Cause Analysis
Invalid unit directives, missing executable paths, permission issues, or unsatisfied service dependencies.
Quick Triage
Run systemctl status and journalctl -u -n 100 –no-pager for immediate failure context.
Step-by-Step Diagnosis
Validate unit syntax with systemd-analyze verify, inspect ExecStart path, and confirm required environment files exist.
Solution – Primary Fix
Fix unit file or dependency order, run sudo systemctl daemon-reload, then restart and enable the service.
Still having issues? Our IT Solutions & Services team can diagnose and resolve this for you. Get in touch for a free consultation.
Solution – Alternative Approaches
Use drop-in overrides under /etc/systemd/system/.d to avoid editing vendor unit files directly.
Verification & Acceptance Criteria
systemctl is-active returns active, logs are clean of repeated failures, and dependent services start normally.
Rollback Plan
Restore previous unit file from backup and reload daemon to return to known-good behavior.
Prevention & Hardening
Version-control unit files, add health checks, and configure Restart policies with sensible backoff.
Related Errors & Cross-Refs
Main process exited, failed with result exit-code, and dependency failed for target messages.
Related tutorial: View the step-by-step tutorial for Ubuntu 18.04 LTS.
View all Ubuntu 18.04 LTS tutorials on the Tutorials Hub →
Browse all common problems & solutions on the Tutorials Hub.
References & Further Reading
man systemd.service, man journalctl, and systemd.unit documentation.
Need Expert Help?
If you cannot resolve this yourself, our team offers hands-on Server Management, Managed IT Services, and flexible Support Plans. Contact us today — we respond within one business day.
