IBM AIX 7.3 – Common Problem 249 – 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

Writes to /tmp fail with ‘No space left on device’ even though df -g shows free blocks.

Environment & Reproduction

Apps that create millions of small files in /tmp exhaust the inode pool.

Root Cause Analysis

JFS2 was created with default nbpi; inode usage hits 100% while blocks are still free.

Quick Triage

Run df -v /tmp to see %Iused and du -sm /tmp/* to find directories with many small files.

Step-by-Step Diagnosis

Inspect /tmp owners with ls -1U /tmp | wc -l and find /tmp -xdev -type f | wc -l.

Solution – Primary Fix

Clear obsolete files, then grow inode count by recreating /tmp with smaller nbpi via crfs.

Solution – Alternative Approaches

Move the heavy producer to a dedicated JFS2 with tuned nbpi or to /var/tmp.

Verification & Acceptance Criteria

df -v /tmp shows %Iused < 50% and application writes resume.

Rollback Plan

If the new /tmp causes regressions, revert to the previous LV from mksysb.

Prevention & Hardening

Cap producer behavior with file age cleanups and per-app temp directories.

Related Errors & Cross-Refs

Often co-occurs with jfs2-filesystem-full alerts.

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 crfs and nbpi tuning guidance.