IBM AIX 7.2 – Common Problem 130 – 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

`topas` shows 100% physc consumption and entitled capacity is exhausted on a shared LPAR.

Environment & Reproduction

AIX 7.2 uncapped SPLPAR with `lparstat` reporting high `app` headroom on the frame.

Root Cause Analysis

A misbehaving process is spinning, or VPs are too few for the workload.

Quick Triage

Open `topas -P` and `nmon -t` to identify the top consumer.

Step-by-Step Diagnosis

Capture `ps -ekf -o pid,pcpu,user,args | sort -k2 -nr | head` and a `procstack` of the top PID.

Solution – Primary Fix

Renice or kill the runaway: `renice 20 ` or `kill -TERM ` after capturing data.

Solution – Alternative Approaches

Increase VPs with `chhwres -r proc -m -o a -p –procunits 0.5 –procs 2`.

Verification & Acceptance Criteria

`topas` returns to baseline physc and `lparstat 5 5` shows normal entitlement usage.

Rollback Plan

Revert VP changes with `chhwres -r proc -m -o r` if the workload no longer needs them.

Prevention & Hardening

Set `schedo -p -o vpm_xvcpus=1` and tune WLM classes for the noisy workload.

Related Errors & Cross-Refs

Pairs with `SC_TAPE_ERR1` false positives and PowerVM `H_BUSY` hypervisor calls.

Related tutorial: View the step-by-step tutorial for aix-7.2.

View all aix-7.2 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

IBM Docs: `topas`, `nmon`, `lparstat`, PowerVM SPLPAR tuning guide.