IBM AIX 7.3 – Common Problem 118 – 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

Multiple LPARs slow; topas_cec shows shared pool at 100%.

Environment & Reproduction

Over-committed shared processor pool on the frame.

Root Cause Analysis

Uncapped LPARs starve each other; entitlement too low.

Quick Triage

Run topas_nmon -C and topas_cec -E for pool stats.

Step-by-Step Diagnosis

Cross-check HMC ‘lssyscfg -r lpar -F name,curr_proc_units’.

Solution – Primary Fix

Raise entitlement via chhwres on HMC; cap noisy LPARs.

Solution – Alternative Approaches

Add CPUs to shared pool from inactive LPAR via DLPAR.

Verification & Acceptance Criteria

Shared pool utilization stays below 80% over peak hours.

Rollback Plan

Reduce entitlement back if pool runs cold.

Prevention & Hardening

Document entitlement plan per LPAR with weights.

Related Errors & Cross-Refs

Pairs with high lparstat phint counts.

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: PowerVM shared processors.