IBM AIX 7.3 – Common Problem 51 – 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

errpt shows DISK_ERR4 PEND entries and I/O latency spikes on rootvg disks.

Environment & Reproduction

Aging hdisks attached via vSCSI or SAN with intermittent fabric errors.

Root Cause Analysis

Underlying LUN reports medium errors; PCM retries mask faults until threshold.

Quick Triage

Run errpt -a | more and lspath -F’name:status’ for failed paths.

Step-by-Step Diagnosis

Use errpt -a -j to inspect sense data and lsmpio -ql hdiskN for SAN paths.

Solution – Primary Fix

Replace failing disk with replacepv, then update firmware via diag -d hdiskN.

Solution – Alternative Approaches

Migrate LV with migratepv to a healthy hdisk before removal.

Verification & Acceptance Criteria

errpt -d H -T PERM returns no DISK_ERR4 for 24h after fix.

Rollback Plan

Reattach original disk with extendvg and reducevg if replacement fails.

Prevention & Hardening

Schedule weekly errpt review and enable AIX Predictive Failure Analysis.

Related Errors & Cross-Refs

DISK_ERR1/2/3, LVM_SA_QUORCLOSE on shared volume groups.

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 AIX 7.3 Storage Management and errpt reference.