IBM AIX 7.1 – Common Problem 019 – 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

mksysb to tape aborts citing write errors and tctl status reports media error.

Environment & Reproduction

IBM AIX 7.2 LPAR exhibiting backup / mksysb tape failure issues under standard PowerVM workloads.

tctl -f /dev/rmt0 status
lsdev -Cc tape

Root Cause Analysis

Dirty tape head or expired media triggers write retries.

Quick Triage

Confirm scope with errpt, recent changes, and subsystem state via lssrc.

errpt -d H -t tape
lsdev -Cc tape

Step-by-Step Diagnosis

Inspect drive status, clean head, and validate media block size.

tctl -f /dev/rmt0 rewind
bosboot -d /dev/rmt0 -a

Solution – Primary Fix

Recreate mksysb to disk image or NIM, then duplicate to tape.

mksysb -i /backup/mksysb.image
smit nim_mksysb_res

Solution – Alternative Approaches

Use IBM Spectrum Protect (TSM) backup as primary path.

Verification & Acceptance Criteria

Confirm subsystem returns to RUNNING state and errpt shows no new entries.

lsmksysb -l /backup/mksysb.image
lsdev -Cc tape

Rollback Plan

Restore prior configuration from mksysb or alt_disk_install clone if the fix regresses.

rm /backup/mksysb.image  # only after replacement validated

Prevention & Hardening

Encode the fix in NIM customisation scripts and monitor via topas/nmon.

smit chgssys  # schedule weekly mksysb and verify

Related Errors & Cross-Refs

tape drive errpt; bos.sysmgt.sysbr level mismatch

Related tutorial: View the step-by-step tutorial for aix-7.1.

View all aix-7.1 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

AIX System Backup and Recovery