IBM AIX 7.3 – Common Problem 011 – 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

MPIO paths show Failed and lsmpio reports degraded for SAN-attached hdisks.

Environment & Reproduction

IBM AIX 7.3 LPAR exhibiting HBA / Fibre Channel disk issues under standard PowerVM workloads.

lsdev -Cc adapter | grep fcs
lsmpio -l hdisk2

Root Cause Analysis

Failed SAN switch port or HBA firmware mismatch removes a path from the MPIO group.

Quick Triage

Confirm scope with errpt, recent changes, and subsystem state via lssrc.

lsmpio -l hdisk2
errpt | grep fcs

Step-by-Step Diagnosis

Inspect fcstat counters and confirm SAN zoning.

fcstat fcs0
lsmpio -ar

Solution – Primary Fix

Re-enable the failed path with chpath after the SAN issue is resolved.

chpath -l hdisk2 -p fscsi0 -s enable

Solution – Alternative Approaches

Replace HBA via DLPAR and re-run cfgmgr to rediscover paths.

Verification & Acceptance Criteria

Confirm subsystem returns to RUNNING state and errpt shows no new entries.

lsmpio -l hdisk2
fcstat fcs0

Rollback Plan

Restore prior configuration from mksysb or alt_disk_install clone if the fix regresses.

chpath -l hdisk2 -p fscsi0 -s disable

Prevention & Hardening

Encode the fix in NIM customisation scripts and monitor via topas/nmon.

smit fcs  # firmware update schedule

Related Errors & Cross-Refs

errpt LABEL=SC_DISK_ERR4; path failed events

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

AIX MPIO and PCM tuning