FreeBSD 14 – UFS Filesystem Marked Dirty After Crash – fsck Recovery Procedure

📖 ~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

System boots into maintenance path due to dirty UFS requiring manual checks.

Environment & Reproduction

Triggered by abrupt power loss or kernel panic during write-intensive activity.

mount
cat /etc/fstab

Root Cause Analysis

Journal/inode state is inconsistent after unclean shutdown and must be reconciled.

Quick Triage

Boot single-user and avoid mounting writable before filesystem checks complete.

fsck -fy

Step-by-Step Diagnosis

Identify affected devices and review fsck pass output for recurring corruption.

gpart show
fsck -n /dev/ada0p2

Solution – Primary Fix

Run forced fsck, repair metadata, and reboot into multi-user mode.

fsck -fy /dev/ada0p2
reboot

Solution – Alternative Approaches

Restore from backup if repeated corruption indicates deeper disk failure.

Verification & Acceptance Criteria

Filesystem mounts cleanly and no immediate fsck rerun is requested.

mount | grep 'on / '
dmesg | tail -n 50

Rollback Plan

Use rescue media and backup restore if repair introduces data loss concerns.

Prevention & Hardening

Improve power protection and monitor disk health to reduce unclean shutdown risks.

Related Errors & Cross-Refs

UNEXPECTED SOFT UPDATE INCONSISTENCY, FILE SYSTEM DIRTY, fsck required.

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 UFS and fsck operational documentation.