IBM AIX 7.3 – Common Problem 81 – Diagnosis and Fix

📖 ~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

fsck reports a bad JFS2 superblock and the FS will not mount.

Environment & Reproduction

Triggered by abrupt power loss or LV resize gone wrong.

Root Cause Analysis

Primary superblock is unreadable while the secondary may be intact.

Quick Triage

Try mount and capture mount: 0506-324 messages from errpt.

Step-by-Step Diagnosis

Run fsck -p -V jfs2 /dev/lvname for an initial assessment.

Solution – Primary Fix

Restore via fsck -y -V jfs2 -o sb=1 /dev/lvname using the alt SB.

Solution – Alternative Approaches

Alternative: logredo /dev/loglv then re-attempt fsck -y.

Verification & Acceptance Criteria

Verify mount succeeds and df -k shows expected free space.

Rollback Plan

Keep an mksysb and savevg before retrying any FS surgery.

Prevention & Hardening

Enable inline log monitoring and avoid forced LV shrinks.

Related Errors & Cross-Refs

Related: 0506-342 and J2_LOG_WRAP entries in the AIX error log.

Related tutorial: View the step-by-step tutorial for aix-7.3.

View all aix-7.3 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

IBM Docs: fsck for JFS2 and logform reference.