Operation Manual

Providing Block Special Files
For each loaded module, the Kernel generates device events. udev handles these
events and generates the required block special les on a RAM le system in /dev.
Without those special les, the le system and other devices would not be accessi-
ble.
Managing RAID and LVM Setups
If you congured your system to hold the root le system under RAID or LVM,
init sets up LVM or RAID to enable access to the root le system later. Find infor-
mation about RAID and LVM in Chapter 3, Advanced Disk Setup (page 73).
Managing Network Conguration
If you congured your system to use a network-mounted root le system (mounted
via NFS), init must make sure that the proper network drivers are loaded and that
they are set up to allow access to the root le system.
When init is called during the initial boot as part of the installation process, its tasks
differ from those mentioned above:
Finding the Installation Medium
As you start the installation process, your machine loads an installation Kernel and
a special initrd with the YaST installer on the installation medium. The YaST
installer, which is run in a RAM le system, needs to have information about the
location of the installation medium to access it and install the operating system.
Initiating Hardware Recognition and Loading Appropriate Kernel Modules
As mentioned in Section 17.1.1, “initramfs” (page 234), the boot process starts
with a minimum set of drivers that can be used with most hardware congurations.
init starts an initial hardware scanning process that determines the set of drivers
suitable for your hardware conguration. The names of the modules needed for
the boot process are written to INITRD_MODULES in /etc/sysconfig/
kernel. These names are used to generate a custom initramfs that is needed
to boot the system. If the modules are not needed for boot but for coldplug, the
modules are written to /etc/sysconfig/hardware/hwconfig-*. All
devices that are described with conguration les in this directory are initialized
in the boot process.
236 Reference