Kernel Updated but Reboot Not Performed

📖 ~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

Security scan still flags old kernel even though dnf update installed a newer kernel package.

Environment & Reproduction

Server has not been rebooted, so old kernel remains active in memory.

Root Cause Analysis

Compare: uname -r with rpm -q kernel –last | head -n 1.

Quick Triage

Confirm bootloader default and ensure no pending maintenance windows block reboot.

Step-by-Step Diagnosis

Record command output showing currently running kernel differs from latest installed.

Solution – Primary Fix

Capture evidence that the new kernel is active after reboot.

Solution – Alternative Approaches

Notify stakeholders and schedule controlled reboot using standard change process.

Verification & Acceptance Criteria

Run: sudo systemctl reboot.

Rollback Plan

After startup, verify services with systemctl –failed and restart any affected unit.

Prevention & Hardening

Confirm uname -r matches latest installed kernel package version.

Related Errors & Cross-Refs

Use patch automation that includes coordinated reboot workflow and verification.

Related tutorial: View the step-by-step tutorial for rhel-9.

View all rhel-9 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

If needed, boot previous kernel from GRUB advanced options and investigate regressions.