3 Changing Kernel Boot Parameters Before Booting

To make a temporary change to the boot parameters before booting a kernel, follow these steps:

1. Select the kernel in the GRUB boot menu.

   When the GRUB boot menu appears at the beginning of the boot process, use the arrow keys to highlight the required kernel and press the space bar.

2. Press E to edit the boot configuration for the kernel.
3. Move the cursor to the line starting with linux.

   Use the arrow keys to bring the cursor to the end of the line that starts with linux, which is the boot configuration line for the kernel.

4. Change the boot parameters.

   You can add parameters such as systemd.target=runlevel1.target, which instructs the system to boot into the rescue shell.

   See Kernel Boot Parameter Reference for more information about kernel parameters.

5. Press Ctrl+X to boot the system.

The kernel boots with the new parameters that you specified on the kernel command line. As noted, the changes are temporary and are only active for the current boot session. If you reboot the system, the changes are reverted. You might want to update the GRUB configuration to make changes permanent. You can edit the GRUB configuration after the system is booted. See Changing GRUB 2 Default Kernel Boot Parameters. A better approach is to use grubby. See Changing Kernel Command Line Boot Parameters for more information.