4.5. Changing kernel command-line parameters temporarily at boot time

Procedure

1. Boot into the GRUB boot menu.
2. Select the kernel you want to start.
3. Press the e key to edit the kernel parameters.
4. Find the kernel command line by moving the cursor down.
5. Move the cursor to the end of the line.

6. Edit the kernel parameters as required. For example, to run the system in emergency mode, add the emergency parameter at the end of the linux line:

   linux   ($root)/vmlinuz-6.12.0-0.el10_0.x86_64 root=/dev/mapper/rhel-root ro crashkernel=2G-64G:256M,64G-:512M resume=/dev/mapper/rhel-swap rd.lvm.lv=rhel/root rd.lvm.lv=rhel/swap rhgb quiet emergency

   To enable the system messages, remove the rhgb and quiet parameters.

7. Press Ctrl+x to boot with the selected kernel and the modified command line parameters.

   重要

   If you press the Esc key to leave command line editing, it will drop all the user made changes.