2.2 Installation Process

The boot process of a system being installed must execute other routines than the boot process of of a system already installed. Some of these routines are executed in the background while other routines may require human intervention.

The routines and modules that are necessary to install a new SLES based system are contained in a special initrd provided by the boot medium. This typically large initrd differs dramatically from the initrd used during a normal operating system boot.

SLES based systems use linuxrc to setup the installation environment. linuxrc accepts custom boot options to influence how the system will be installed. Some options ensure a proper network setup, if necessary. Other parameters determine which installation repositories shall be used. An unattended installation via AutoYaST is initiated by specifying the autoyast= boot option:

autoyast=<URL to AutoYaST control file>

This parameter is recognized by the initrd and the installation process is taking another direction. Instead of prompting the administrator for various system settings an AutoYaST control file is retrieved from the URL specified. YaST modules then parse the control file and perform an unattended installation according to the information provided in the AutoYaST control file.

Once all actions specified in the control file have been executed the system being installed is automatically rebooted.