SLES 16 – Common Problem 149 – 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 patching an Azure SLES 16 VM, both `kernel-default` and `kernel-azure` are installed and the wrong one boots.

Environment & Reproduction

Reproduces when admins run `zypper install kernel-default` on a hyperscaler image.

Root Cause Analysis

Hyperscaler images ship a tuned kernel flavor; mixing flavors confuses GRUB defaults.

Quick Triage

Check installed kernels: `rpm -qa kernel-*` and `grub2-editenv list`.

Step-by-Step Diagnosis

Inspect `/etc/sysconfig/kernel` for the configured `KERNEL` line and flavor list.

Solution – Primary Fix

Remove the unwanted flavor: `zypper rm kernel-default` and `dracut -f`.

Solution – Alternative Approaches

Lock the cloud flavor: `zypper addlock kernel-azure-*` to prevent future drift.

Verification & Acceptance Criteria

`uname -r` reports the expected hyperscaler flavor and `lsmod` shows tuned drivers.

Rollback Plan

Restore the previous bootloader entry via snapper if removal breaks boot.

Prevention & Hardening

Bake the kernel-flavor policy into the cloud image build pipeline.

Related Errors & Cross-Refs

Pairs with hyperscaler agent failures when drivers don’t match.

Related tutorial: View the step-by-step tutorial for sles-16.

View all sles-16 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

SUSE public cloud image notes for Azure/AWS/GCP.