Novell LINUX ENTERPRISE SERVER 10 SP2 - INSTALLATION AND ADMINISTRATION Installation Manual page 425

access file systems of supported BIOS disk devices (floppy disks or hard disks, CD
drives, and DVD drives detected by the BIOS). Therefore, changes to the GRUB con-
figuration file (menu.lst) do not require a reinstallation of the boot manager. When
the system is booted, GRUB reloads the menu file with the valid paths and partition
data of the kernel or the initial RAM disk (initrd) and locates these files.
The actual configuration of GRUB is based on three files that are described below:
/boot/grub/menu.lst
This file contains all information about partitions or operating systems that can be
booted with GRUB. Without this information, the GRUB command line prompts
the user for how to proceed (see Section "Editing Menu Entries during the Boot
Procedure" (page 412) for details).
/boot/grub/device.map
This file translates device names from the GRUB and BIOS notation to Linux device
names.
/etc/grub.conf
This file contains the commands, parameters, and options the GRUB shell needs
for installing the boot loader correctly.
GRUB can be controlled in various ways. Boot entries from an existing configuration
can be selected from the graphical menu (splash screen). The configuration is loaded
from the file menu.lst.
In GRUB, all boot parameters can be changed prior to booting. For example, errors
made when editing the menu file can be corrected in this way. Boot commands can also
be entered interactively at a kind of input prompt (see Section "Editing Menu Entries
during the Boot Procedure" (page 412)). GRUB offers the possibility of determining
the location of the kernel and the initrd prior to booting. In this way, you can even
boot an installed operating system for which no entry exists in the boot loader configu-
ration.
GRUB actually exists in two versions: as a boot loader and as a normal Linux program
in /usr/sbin/grub. This program is referred to as the GRUB shell. It provides an
emulation of GRUB in the installed system and can be used to install GRUB or test
new settings before applying them. The functionality to install GRUB as the boot
loader on a hard disk or floppy disk is integrated in GRUB in the form of the commands
install and setup. This is available in the GRUB shell when Linux is loaded.
The Boot Loader 407