CentOS Stream 9 – Common Problem 231 – 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

BLS entries vanish after kernel install

Environment & Reproduction

grubby fails because /boot/loader/entries is missing or unwritable.

Root Cause Analysis

kernel-install hook cannot create BLS entry due to missing directory or SELinux.

Quick Triage

Check ls /boot/loader/entries and journalctl -u kernel-install.

Step-by-Step Diagnosis

Run: rpm -qa kernel; sudo grubby –info=ALL; ls /boot/loader/entries.

Solution – Primary Fix

sudo mkdir -p /boot/loader/entries; sudo dnf reinstall kernel-core; sudo grub2-mkconfig -o /boot/grub2/grub.cfg.

Solution – Alternative Approaches

Switch back to grub.cfg-only entries by setting GRUB_ENABLE_BLSCFG=false then regenerating config.

Verification & Acceptance Criteria

After reboot, grubby –default-kernel returns the newest kernel and the menu lists it.

Rollback Plan

Boot from previous kernel via grub menu and rerun grub2-mkconfig.

Prevention & Hardening

Protect /boot/loader/entries permissions and exclude from automated cleanup scripts.

Related Errors & Cross-Refs

Pairs with rescue-mode prompts and missing initramfs warnings.

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

BootLoaderSpec docs and grubby(8).