IBM AIX 7.3 – Common Problem 162 – 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

Scheduled mksysb backups fail to complete leaving rootvg without recent disaster-recovery image.

Environment & Reproduction

Affects mksysb runs that build a bootable image to disk or NIM server.

df -g /tmp
oslevel -s
uname -a

Root Cause Analysis

Cause is /tmp shortage during image creation, or excluded filesystems not being honoured because of /etc/exclude.rootvg syntax errors.

Quick Triage

Check /tmp, exclude file, and backup destination.

df -g /tmp

Step-by-Step Diagnosis

Capture deeper evidence to isolate the failure path.

df -g /tmp
wc -l /etc/exclude.rootvg
lsvg rootvg
ls -l /mksysb
errpt | head

Solution – Primary Fix

Apply the proven primary fix in a controlled change window.

chfs -a size=+2G /tmp
mksysb -i -X /mksysb/$(hostname).mksysb
smitty mksysb

Solution – Alternative Approaches

Use these alternatives when the primary fix is blocked by environmental constraints.

nim -o define -t mksysb -a source=$(hostname) bkp_$(hostname)
savevg -if /backup/datavg.bk datavg

Verification & Acceptance Criteria

Confirm the system meets acceptance criteria after the change.

ls -l /mksysb
restore -Tqf /mksysb/$(hostname).mksysb | head
bootinfo -b

Rollback Plan

Revert cleanly if regressions appear during validation.

rm /mksysb/$(hostname).mksysb
chfs -a size=-2G /tmp
bootlist -m normal hdisk0

Prevention & Hardening

Reduce recurrence with monitoring and preventive tuning.

crontab -l | grep mksysb
fuser -kxuc /tmp
emgr -l

Related Errors & Cross-Refs

Related to NIM resource definitions, tape device issues, and ssh transfer failures.

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 Backup and Recovery guide, mksysb man page.