Failed to Mount CIFS Share at Boot

📖 ~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

Boot hangs or fails due to blocking mount of unreachable CIFS network share.

Environment & Reproduction

Ubuntu 18.04 hosts with static fstab CIFS entries and intermittent network availability.

Root Cause Analysis

Mount attempts occur before network readiness or use invalid credentials/options.

Quick Triage

Review fstab CIFS options and check network reachability to share server.

Step-by-Step Diagnosis

Analyze boot logs, mount unit behavior, and SMB authentication outcomes.

Solution – Primary Fix

Use nofail and systemd automount options with validated credentials and proper dependencies.

Solution – Alternative Approaches

Mount on-demand via scripts or use autofs for dynamic network share handling.

Verification & Acceptance Criteria

System boots without delay and share mounts successfully when network is available.

Rollback Plan

Temporarily disable fstab entry if mount behavior remains unstable in production.

Prevention & Hardening

Enforce robust mount options and monitor SMB endpoint health proactively.

Related Errors & Cross-Refs

mount error(113), dependency failed for remote file systems, and credential permission issues.

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

cifs-utils and systemd mount unit documentation for network filesystem reliability.