IBM AIX 7.2 – Common Problem 093 – 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

Client LPAR loses a virtual disk after VIOS update or reboot.

Environment & Reproduction

Triggered by vhost mapping drift or backing device renumbering.

Root Cause Analysis

vSCSI client cannot find the expected hdisk in cfgmgr output.

Quick Triage

On VIOS run lsmap -all and confirm the expected vtscsi mappings.

Step-by-Step Diagnosis

On client check errpt for VSCSI_ERR4 and run cfgmgr -v.

Solution – Primary Fix

Re-map on VIOS with mkvdev -vdev hdiskN -vadapter vhostX -dev vtscsiN.

Solution – Alternative Approaches

Alternative: padmin script that re-asserts mappings from a backup file.

Verification & Acceptance Criteria

Verify the client sees the disk via lspv and uses lsattr -El hdiskN.

Rollback Plan

Take a viosbr -backup before VIOS maintenance to allow viosbr -restore.

Prevention & Hardening

Pin disk reservation policies and unique_id on VIOS for stability.

Related Errors & Cross-Refs

Related: VIOS_MAPPING_LOST and client VSCSI timeouts.

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 Docs: viosbr and vSCSI mapping management.