📖 ~1 min read
Table of contents
Symptom & Impact
After yum kernel updates, RHEL 7 continues booting an older kernel due to GRUB default entry configuration.
Environment & Reproduction
rpm shows newer kernel installed, but uname -r reports previous version after reboot.
Root Cause Analysis
Incorrect saved_entry, manual grub edits, failed grub2-mkconfig updates, or booting alternate menu entry.
Quick Triage
Check rpm -q kernel, grub2-editenv list, and /etc/default/grub settings before changing boot defaults.
Step-by-Step Diagnosis
Use journalctl -b and boot logs to confirm which kernel image loaded during startup.
Solution – Primary Fix
Inspect grub.cfg entries and saved default values to map expected kernel index and title.
Still having issues? Our IT Solutions & Services team can diagnose and resolve this for you. Get in touch for a free consultation.
Solution – Alternative Approaches
Set the intended kernel as default using grub2-set-default, regenerate grub config if required, and reboot for validation.
Verification & Acceptance Criteria
SELinux and firewalld are not direct causes, but post-kernel reboot should include policy and networking sanity checks.
Rollback Plan
After reboot, verify uname -r and confirm core services start normally with systemctl status.
Prevention & Hardening
Select prior kernel entry from GRUB menu if new kernel causes regressions, then reset default accordingly.
Related Errors & Cross-Refs
Automate post-update kernel validation and track bootloader default settings in configuration management.
Related tutorial: View the step-by-step tutorial for rhel-7.
View all rhel-7 tutorials on the Tutorials Hub →
Browse all common problems & solutions on the Tutorials Hub.
References & Further Reading
Refer to grub2 and kernel management documentation for RHEL 7 maintenance operations.
Need Expert Help?
If you cannot resolve this yourself, our team offers hands-on Server Management, Managed IT Services, and flexible Support Plans. Contact us today — we respond within one business day.
