RHEL Booting into an Old Kernel? Here’s the Fix

 On my RHEL 8.10 system, I noticed that even though the latest kernel was installed, the server kept booting with an older one.

The Cause

GRUB was configured to use the last saved kernel entry (saved_entry) instead of automatically picking the most recent kernel.

The Solution

The fix was simple: edit the GRUB configuration and tell it to always boot the first entry (which is the newest kernel).

1. Open /etc/default/grub and set:

   GRUB_DEFAULT=0
   

2. Regenerate the GRUB configuration:

   • BIOS:

     grub2-mkconfig -o /boot/grub2/grub.cfg
     

   • UEFI:

     grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg
     

3. Reboot the server:

   reboot
   

After that, the system automatically boots into the latest installed kernel every time. 🚀