IBM AIX 7.3 – Common Problem 243 – 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

An entry in /etc/inittab respawns endlessly, filling /var/adm/messages and starving CPU.

Environment & Reproduction

Introduced when a custom daemon was added to inittab without proper exit handling.

Root Cause Analysis

init detects rapid process exits and respawns more than once per 2 minutes, leading to throttling messages.

Quick Triage

Run last reboot and tail /var/adm/messages for init: Command finished respawning too rapidly.

Step-by-Step Diagnosis

Inspect /etc/inittab and the failing command output directly under a shell.

Solution – Primary Fix

Edit /etc/inittab to switch the entry to once or off, then run telinit q.

Solution – Alternative Approaches

Replace the entry with a proper SRC subsystem registered via mkssys.

Verification & Acceptance Criteria

ps -ef does not show the runaway command and /var/adm/messages stops respawning warnings.

Rollback Plan

Restore the previous inittab from backup and rerun telinit q if SRC migration fails.

Prevention & Hardening

Use SRC (startsrc/stopsrc) for long-running daemons instead of raw inittab respawn.

Related Errors & Cross-Refs

May coincide with high runq and syslog flooding.

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 init and SRC command references.