Installation guide
Configuring a GRUB menu configuration file to boot multiple operating systems is beyond the scope
of this chapter. Consult Section 9.9, “ Additional Resources” for a list of additional resources.
9.7.2. Configurat ion File Direct ives
The following are directives commonly used in the GRUB menu configuration file:
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, +1.
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 default
entry when the timeout period 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 root command, but does not mount the partition.
timeout=<integer> — Specifies the interval, in seconds, that GRUB waits before loading the
entry designated in the default command.
Chapt er 9 . T he G RUB Boot Loader
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