Novell LINUX ENTERPRISE SERVER 11 - ADMINISTRATION Administration Manual page 76

remaining part of the boot process. Therefore, the first 512 bytes on the first hard
disk are referred to as the Master Boot Record (MBR). The boot loader then
passes control to the actual operating system, in this case, the Linux kernel. More
information about GRUB, the Linux boot loader, can be found in
Boot Loader GRUB
loader. It gets the image to start from the boot server then starts the system. This
is completely independent of local hard disks.
3. Kernel and initramfs
kernel and an initial RAM–based file system (initramfs) into memory. The contents
of the initramfs can be used by the kernel directly. initramfs contains a small exe-
cutable called init that handles the mounting of the real root file system. If special
hardware drivers are needed before the mass storage can be accessed, they must
be in initramfs. For more information about initramfs, refer to
"initramfs"
must provide the root file system to the kernel. This can be done with the help of
a network block device like iSCSI or SAN, but it is also possible to use NFS as
the root device.
4. init on initramfs
proper root file system, like providing kernel functionality for the needed file
system and device drivers for mass storage controllers with udev. After the root
file system has been found, it is checked for errors and mounted. If this has been
successful, the initramfs is cleaned and the init program on the root file system is
executed. For more information about init, refer to
(page 63). Find more information about udev in
Device Management with udev
5. init
providing different functionality. init is described in
(page 65).
7.1.1 initramfs
initramfs is a small cpio archive that the kernel can load to a RAM disk. It provides a
minimal Linux environment that enables the execution of programs before the actual
root file system is mounted. This minimal Linux environment is loaded into memory
by BIOS routines and does not have specific hardware requirements other than sufficient
62 Administration Guide
(page 77). For a network boot, the BIOS acts as the boot
To pass system control, the boot loader loads both the
(page 62). If the system does not have a local hard disk, the initramfs
This program performs all actions needed to mount the
init handles the actual booting of the system through several different levels
Section 7.1.2, "init on initramfs"
Chapter 11, Dynamic Kernel
(page 131).
Section 7.2, "The init Process"
Chapter 8, The
Section 7.1.1,