IBM AIX 7.1 – Common Problem 203 – 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

System slows or processes are killed by the kernel when paging space is exhausted.

Environment & Reproduction

High memory pressure on hdisk-backed paging or insufficient hd6 size.

lsps -a
vmstat 2 5
svmon -G

Root Cause Analysis

Active paging space (hd6 and others) is too small or one paging LV is full.

Quick Triage

Confirm paging usage and active processes consuming memory.

lsps -s
topas -P
svmon -P -O sortseg=pgsp

Step-by-Step Diagnosis

Identify processes and check paging device layout for balance.

ps gv | head
svmon -P -O sortseg=pgsp
lsps -a

Solution – Primary Fix

Add or extend paging space and balance across disks, then activate.

chps -s 4 hd6
mkps -a -n -s 4 rootvg
lsps -a

Solution – Alternative Approaches

Tune vmo paging parameters or migrate workloads to LPAR with more memory.

Verification & Acceptance Criteria

vmstat shows reduced paging activity and lsps -a reports headroom.

vmstat 2 3
lsps -s
svmon -G

Rollback Plan

Deactivate and remove the added paging space if it caused contention.

swapoff /dev/paging01
rmps paging01
lsps -a

Prevention & Hardening

Size paging at 1-2x RAM for general workloads and monitor with nmon.

Related Errors & Cross-Refs

Related to OOM-like process kills, slow logins, and vmstat -v faults.

Related tutorial: View the step-by-step tutorial for aix-7.1.

View all aix-7.1 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

IBM AIX 7.2 performance management and paging space guide.