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25.3. Making Temporary Changes to a GRUB 2 Menu
Procedure 25.1. Making Temporary Changes to a Kernel Menu Entry
To change kernel parameters only during a single boot process, proceed as follows:
- Start the system and, on the GRUB 2 boot screen, move the cursor to the menu entry you want to edit, and press the e key for edit.
- Move the cursor down to find the kernel command line. The kernel command line starts with
linuxon 64-Bit IBM Power Series,linux16on x86-64 BIOS-based systems, orlinuxefion UEFI systems. - Move the cursor to the end of the line.Press Ctrl+a and Ctrl+e to jump to the start and end of the line, respectively. On some systems, Home and End might also work.
- Edit the kernel parameters as required. For example, to run the system in emergency mode, add the emergency parameter at the end of the
linux16line:linux16 /vmlinuz-3.10.0-0.rc4.59.el7.x86_64 root=/dev/mapper/rhel-root ro rd.md=0 rd.dm=0 rd.lvm.lv=rhel/swap crashkernel=auto rd.luks=0 vconsole.keymap=us rd.lvm.lv=rhel/root rhgb quiet emergencyTherhgbandquietparameters can be removed in order to enable system messages.These settings are not persistent and apply only for a single boot. To make persistent changes to a menu entry on a system, use thegrubbytool. See the section called “Adding and Removing Arguments from a GRUB 2 Menu Entry” for more information on usinggrubby.
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