IBM AIX 7.2 – Common Problem 151 – 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

After applying a kernel fileset update, bosboot returns errors and the system cannot create a usable boot image. A reboot at this point risks an unbootable LPAR.

Environment & Reproduction

Occurs on rootvg after installp or suma updates that touch bos.mp64 or device filesets.

oslevel -s
oslevel -s
uname -a

Root Cause Analysis

Most cases trace to a missing boot logical volume, corrupted /usr/lib/boot, or a hdisk path issue in MPIO that blocks writing the boot record.

Quick Triage

Confirm rootvg state, boot device path, and free space in /tmp and /usr before retrying bosboot.

oslevel -s

Step-by-Step Diagnosis

Capture deeper evidence to isolate the failure path.

oslevel -s
lslpp -l bos.mp64
lsvg -l rootvg | grep hd5
bootlist -m normal -o
lspath -l hdisk0

Solution – Primary Fix

Apply the proven primary fix in a controlled change window.

bosboot -ad /dev/ipldevice
bootlist -m normal hdisk0
savebase -v
bosboot -ad /dev/hdisk0

Solution – Alternative Approaches

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

multibos -Xac
multibos -S
bootlist -m normal hdisk0 hdisk1

Verification & Acceptance Criteria

Confirm the system meets acceptance criteria after the change.

bosboot -v -ad /dev/ipldevice
bootinfo -b
bootlist -m normal -o

Rollback Plan

Revert cleanly if regressions appear during validation.

bootlist -m normal hdisk0
alt_rootvg_op -W -d hdisk1

Prevention & Hardening

Reduce recurrence with monitoring and preventive tuning.

mksysb -i /mksysb/$(hostname).mksysb
bootlist -m normal hdisk0 hdisk1
errpt | head

Related Errors & Cross-Refs

Often co-occurs with MPIO path failures, full /tmp, or stale ODM entries for hdisk devices.

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 Installation and Migration guide, bosboot and bootlist man pages, IBM Support flash alerts.