IBM AIX 7.2 – Common Problem 227 – 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

Apps get killed or hang and errpt logs PAGING_SPACE_LOW events.

Environment & Reproduction

Triggered when active paging usage approaches lsps -a Used% near 80% on busy LPARs.

Root Cause Analysis

Paging sized for old workload; new JVMs or DB buffers exceed RAM and force heavy pageout.

Quick Triage

Run lsps -a and vmstat 2 5 to see free paging and pi/po activity.

Step-by-Step Diagnosis

Use svmon -G, topas, and ps gv | sort to find top RSS consumers driving pageout.

Solution – Primary Fix

Extend paging with chps -s N hd6 or add a new paging LV via mkps -a -n -s N rootvg.

Solution – Alternative Approaches

Tune vmo minperm%/maxperm% or move heavy JVMs to an LPAR with more entitled memory.

Verification & Acceptance Criteria

lsps -a Used% drops below 50% and PAGING_SPACE_LOW entries stop appearing in errpt.

Rollback Plan

Deactivate added paging with chps -a n hd6N then rmps once the LPAR has been resized.

Prevention & Hardening

Right-size paging to 0.5x-1x RAM and alarm on lsps Used% via nmon or topas recordings.

Related Errors & Cross-Refs

Related to OOM-like process kills and JFS2 write latency under memory pressure.

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 AIX 7.2 Performance Management Guide on paging and VMM tuning.