CentOS Stream 9 – Common Problem 238 – 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

Rootless podman fails to start container

Environment & Reproduction

/etc/subuid or /etc/subgid lacks range for user on CS9.

Root Cause Analysis

newuidmap rejects mapping due to missing or duplicate subordinate UID range.

Quick Triage

podman info reports errors, and getsubids shows nothing.

Step-by-Step Diagnosis

Run: grep /etc/subuid /etc/subgid; podman system migrate.

Solution – Primary Fix

sudo usermod –add-subuids 100000-165535 –add-subgids 100000-165535 .

Solution – Alternative Approaches

Enable lingering and use rootful podman if rootless is not required.

Verification & Acceptance Criteria

podman run –rm hello-world succeeds without errors.

Rollback Plan

Remove subuid entries with usermod –del-subuids and revert.

Prevention & Hardening

Document subuid allocation policy and provision via Ansible.

Related Errors & Cross-Refs

Pairs with cannot create user namespace and newuidmap errors.

Related tutorial: View the step-by-step tutorial for centos-stream-9.

View all centos-stream-9 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

subuid(5) and podman rootless tutorial.