A software boot loader is used to start Red Hat Linux on your computer. It
can also start other operating systems, such as Windows. If you are
using a Red Hat Linux software boot loader (GRUB or LILO), it will be detected
automatically.
In order to be able to boot your Red Hat Linux system, you usually need to
install a boot loader. In Red Hat Linux 7.3, you can choose to install GRUB or
LILO, or you can choose not to install a boot loader at all.
First, select which boot loader you want to install. If you do not
want to overwrite your current boot loader, choose Do not
install a boot loader.
Assuming you chose GRUB or LILO, you must now determine where
you want the boot loader to be installed. You may install the boot
loader in one of two places:
- The master boot record (MBR)
This is the recommended place to install a boot
loader, unless the MBR already starts another operating system
loader, such as System Commander. The MBR is a special area on
your hard drive that is automatically loaded by your computer's
BIOS, and is the earliest point at which the boot loader can
take control of the boot process. If you install it in the MBR,
when your machine boots, GRUB (or LILO) will present a boot
prompt. You can then boot Red Hat Linux or any other operating system
that you have configured the boot loader to boot.
- The first sector of your boot partition
This is recommended if you are already using another
boot loader on your system. In this case, your other boot
loader will take control first. You can then configure that
boot loader to start GRUB (or LILO), which will then boot Red Hat Linux.
If your system will use only Red Hat Linux, you should choose the MBR. For
systems with Windows 95/98, you should also install the boot loader to
the MBR so that it can boot both operating systems.
 | Caution |
|---|
| | If you choose not to install GRUB or LILO
for any reason, you will not be able to boot your Red Hat Linux system
directly, and you will need to use another boot method (such as a
boot diskette). Use this option only if you are sure you have
another way of booting your Red Hat Linux system!
|
If you wish to add default options to GRUB or LILO's boot command,
enter them into the Kernel parameters field. Any
options you enter will be passed to the Linux kernel every time it
boots.
The Force use of LBA32 (not normally
required) option allows you to exceed the 1024 cylinder
limit for the /boot partition. If you have a
system which supports the LBA32 extension for booting operating
systems above the 1024 cylinder limit, and you want to place your
/boot partition above cylinder 1024, you should
select this option.
Every bootable partition is listed, including partitions used by
other operating systems. The partition holding your Red Hat Linux system's
root file system will have a Boot label of
Red Hat Linux (for GRUB) or
linux (for LILO). Other partitions may also have
boot labels. If you would like to add boot labels for other
partitions (or change an existing boot label), click once on the
partition to select it. Once selected, you can change the boot label.
 | Note |
|---|
| | The Boot label column
lists what you must enter at the boot prompt, in non-graphical boot
loaders, in order to boot the desired operating system. However, if
you forget the boot labels defined on your system, you can always
press [Tab] at the prompt to display a list of
defined boot labels.
|
If you need to use rescue mode, there are several options
available to you.
Using the CD-ROM to boot, type linux
rescue at the boot: prompt.
By booting your system from an installation boot diskette
made from the boot.img image. This method
requires that the Red Hat Linux CD-ROM #1 be inserted as the rescue
image or that the rescue image be on the hard drive as an ISO
image. Once you have booted using this diskette, type
linux rescue at the
boot: prompt.
By booting from a network disk made from the
bootnet.img or PCMCIA boot disk made from
pcmcia.img. Once you have booted using this
diskette, type linux rescue at the
boot: prompt. You can only do this if your
network connection is working. You will need to identify the
network host and transfer type. For an explanation of how to
specify this information, see the Section called Preparing for a Network Installation in Chapter 3.
For more information regarding rescue mode, refer to the
Official Red Hat Linux Customization Guide.
If you do not wish to use GRUB or LILO to boot your Red Hat Linux
system, you have several alternatives:
- Boot disk
As previously stated, you can use the boot disk
created by the installation program (if you elected to create
one).
- LOADLIN
You can load Linux from MS-DOS. Unfortunately, this
requires a copy of the Linux kernel (and an initial RAM disk, if
you have a SCSI adapter) to be available on an MS-DOS partition.
The only way to accomplish this is to boot your Red Hat Linux system
using some other method (for example, from a boot disk)
and then copy the kernel to an MS-DOS partition. LOADLIN is
available from
ftp://metalab.unc.edu/pub/Linux/system/boot/dualboot/ |
and associated mirror sites.
- SYSLINUX
SYSLINUX is an MS-DOS program very similar to
LOADLIN. It is also available from
ftp://metalab.unc.edu/pub/Linux/system/boot/loaders/ |
and associated mirror sites.
- Some commercial boot loaders
You can load Linux using commercial boot loaders.
For example, System Commander and Partition Magic are able to
boot Linux (but still require GRUB or LILO to be installed in
your Linux root partition).
This section is specific to SMP motherboards only. SMP, short
for Symmetric Multiprocessing, is a computer architecture providing
fast performance by making multiple CPUs available to complete
individual processes simultaneously (multiprocessing).
If the installation program detects an SMP motherboard on your
system, it will automatically create two
/boot/grub/grub.conf or
/etc/lilo.conf entries (depending on the boot
loader you installed), rather than the usual single entry.
| Note |
|---|
| | IntelŪ PentiumŪ 4 systems with
hyperthreading will have an SMP kernel installed by
default. |
The two entries in grub.conf will be
Red Hat Linux (kernel
version) and Red Hat
Linux (kernel
version-smp). The Red
Hat Linux (kernel
version-smp) will boot by
default. However, if you have trouble with the SMP kernel, you can
elect to boot the Red Hat Linux (kernel
version) entry instead. You will
retain all the functionality as before, but you will only be
operating with a single processor.
The two entries in lilo.conf will be
linux and
linux-up. The
linux entry will boot by
default. However, if you have trouble with the SMP kernel, you can
elect to boot the linux-up entry
instead. You will retain all the functionality as before, but you
will only be operating with a single processor.
