9.7. GRUB Menu Configuration File
/boot/grub/grub.conf), which is used to create the list of operating systems to boot in GRUB's menu interface, essentially allows the user to select a pre-set group of commands to execute. The commands given in Section 9.6, “GRUB Commands” can be used, as well as some special commands that are only available in the configuration file.
9.7.1. Configuration File Structure
/boot/grub/grub.conf. The commands to set the global preferences for the menu interface are placed at the top of the file, followed by stanzas for each operating kernel or operating system listed in the menu.
default=0 timeout=10 splashimage=(hd0,0)/grub/splash.xpm.gz hiddenmenu title Red Hat Enterprise Linux Server (2.6.18-2.el5PAE) root (hd0,0) kernel /boot/vmlinuz-2.6.18-2.el5PAE ro root=LABEL=/1 rhgb quiet initrd /boot/initrd-2.6.18-2.el5PAE.img # section to load Windows title Windows rootnoverify (hd0,0) chainloader +1
titleline in the GRUB configuration file. For the
Windowssection to be set as the default in the previous example, change the
9.7.2. Configuration File Directives
chainloader </path/to/file>— Loads the specified file as a chain loader. Replace </path/to/file> with the absolute path to the chain loader. If the file is located on the first sector of the specified partition, use the blocklist notation,
color <normal-color> <selected-color>— Allows specific colors to be used in the menu, where two colors are configured as the foreground and background. Use simple color names such as
red/black. For example:
color red/black green/blue
default=<integer>— Replace <integer> with the default entry title number to be loaded if the menu interface times out.
fallback=<integer>— Replace <integer> with the entry title number to try if the first attempt fails.
hiddenmenu— Prevents the GRUB menu interface from being displayed, loading the
defaultentry when the
timeoutperiod expires. The user can see the standard GRUB menu by pressing the Esc key.
initrd </path/to/initrd>— Enables users to specify an initial RAM disk to use when booting. Replace </path/to/initrd> with the absolute path to the initial RAM disk.
kernel </path/to/kernel> <option-1> <option-N>— Specifies the kernel file to load when booting the operating system. Replace </path/to/kernel> with an absolute path from the partition specified by the root directive. Multiple options can be passed to the kernel when it is loaded.
password=<password>— Prevents a user who does not know the password from editing the entries for this menu option.Optionally, it is possible to specify an alternate menu configuration file after the
password=<password>directive. In this case, GRUB restarts the second stage boot loader and uses the specified alternate configuration file to build the menu. If an alternate menu configuration file is left out of the command, a user who knows the password is allowed to edit the current configuration file.For more information about securing GRUB, see the chapter titled Workstation Security in the Red Hat Enterprise Linux Deployment Guide.
root (<device-type><device-number>,<partition>)— Configures the root partition for GRUB, such as
(hd0,0), and mounts the partition.
rootnoverify (<device-type><device-number>,<partition>)— Configures the root partition for GRUB, just like the
rootcommand, but does not mount the partition.
timeout=<integer>— Specifies the interval, in seconds, that GRUB waits before loading the entry designated in the
splashimage=<path-to-image>— Specifies the location of the splash screen image to be used when GRUB boots.
title group-title— Specifies a title to be used with a particular group of commands used to load a kernel or operating system.