Novell LINUX ENTERPRISE SERVER 10 - INSTALLATION AND ADMINISTRATION 04-08-2006 Installation Manual page 386

3.
4.
5.
20.1.1 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
memory. initramfs must always provide an executable named init that should execute
the actual init program on the root file system for the boot process to proceed.
386 Installation and Administration
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
ter 21, The Boot Loader
boot loader. It gets the image to start from the boot server then starts the system.
This is completely independent of local hard disks.
Kernel and initramfs
kernel and an initial RAM–based file system (initramfs) into memory. The con-
tents of the initramfs can be used by the kernel directly. initramfs contains a
small executable called init that handles the mounting of the real root file system.
In former versions of SUSE® Linux, these tasks were handled by initrd and
linuxrc, respectively. For more information about initramfs, refer to
tion 20.1.1, "initramfs"
the 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.
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
initramfs" (page 387). Find more information about udev in
Kernel Device Management with udev
init init handles the actual booting of the system through several different
levels providing different functionality. init is described in
init Process" (page 389).
(page 401). For a network boot, the BIOS acts as the
To pass system control, the boot loader loads both the
(page 386). If the system does not have a local hard disk,
This program performs all actions needed to mount the
(page 475).
Chap-
Sec-
Section 20.1.2, "init on
Chapter 25, Dynamic
Section 20.2, "The