How to set the default kernel with grubby.

Question

This article provides the steps to set the default kernel with the grubby command.

Answer

The most efficient way of setting up your default kernel is to use it's index in the boot menu entry.

1. Access the server's command line as the root user via SSH or Terminal in WHM.

2. List the installed kernels.

   #  grubby --info=ALL | grep -E "^kernel|^index"

3. Copy the full path of the kernel you want to set as default.

4. Use the grubby command with the --set-default option to set the default kernel.

   # grubby --set-default-index=0

Additional resources

Changing the Default Kernel

Making persistent changes to the GRUB boot loader: Changing the default boot entry with grubby