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documentation.suse.com / Documentazione di SUSE Linux Enterprise Server / AutoYaST / The Auto-Installation Process
Applies to SUSE Linux Enterprise Server 12 SP5

6 The Auto-Installation Process

6.1 Introduction

After the system has booted into an automatic installation and the control file has been retrieved, YaST configures the system according to the information provided in the control file. All configuration settings are summarized in a window that is shown by default and should be deactivated if a fully automatic installation is needed.

By the time YaST displays the summary of the configuration, YaST has only probed hardware and prepared the system for auto-installation. Nothing has been changed in the system yet. In case of any error, you can still abort the process.

A system should be automatically installable without the need to have any graphic adapter or monitor. Having a monitor attached to the client machine is nevertheless recommended so you can supervise the process and to get feedback in case of errors. Choose between the graphical and the text-based Ncurses interfaces. For headless clients, system messages can be monitored using the serial console.

6.1.1 X11 Interface (graphical)

This is the default interface while auto-installing. No special variables are required to activate it.

6.1.2 Serial console

Start installing a system using the serial console by adding the keyword console (for example console=ttyS0) to the command line of the kernel. This starts linuxrc in console mode and later YaST in serial console mode.

6.1.3 Text-based YaST Installation

This option can also be activated on the command line. To start YaST in text mode, add textmode=1 on the command line.

Starting YaST in the text mode is recommended when installing a client with less than 64 MB or when X11 should not be configured, especially on headless machines.

6.2 Choosing the Right Boot Medium

There are different methods for booting the client. The computer can boot from its network interface card (NIC) to receive the boot images via DHCP or TFTP. Alternatively a suitable kernel and initrd image can be loaded from a flash disk or a bootable DVD-ROM.

YaST will check for autoinst.xml in the root directory of the boot medium or the initrd upon start-up and switch to an automated installation if it was found. In case the control file is named differently or located elsewhere, specify its location on the kernel command line with the parameter AutoYaST=URL.

6.2.1 Booting from a Flash Disk

For testing/rescue purposes or because the NIC does not have a PROM or PXE you can build a bootable flash disk to use with AutoYaST. Flash disks can also store the control file.

Tip
Tip: Creating a Bootable Flash Disk

To create a bootable flash disk, copy either the SUSE Linux Enterprise Server ISO image of DVD1 or the Mini CD ISO image to the disk using the dd command (the flash disk must not be mounted, all data on the device will be erased):

dd if=PATH_TO_ISO_IMAGE of=USB_STORAGE_DEVICE bs=4M

6.2.2 Booting from DVD-ROM

You can use the original SUSE Linux Enterprise Server DVD-ROM number one in combination with other media. For example, the control file can be provided via a flash disk or a specified location on the network. Alternatively, create a customized DVD-ROM that includes the control file.

6.2.3 Booting via PXE over the Network

Booting via PXE requires a DHCP and a TFTP server in your network. The computer will then boot without a physical medium. For instructions on setting up the required infrastructure, see Capitolo 10, Installazione remota.

If you do installation via PXE, the installation will run into an endless loop. This happens because after the first reboot, the machine performs the PXE boot again and restarts the installation instead of booting from the hard disk for the second stage of the installation.

There are several ways to solve this problem. You can use an HTTP server to provide the AutoYaST control file. Alternatively, instead of a static control file, run a CGI script on the Web server that provides the control file and changes the TFTP server configuration for your target host. This way, the next PXE boot of the machine will be from the hard disk by default.

Another way is to use AutoYaST to upload a new PXE boot configuration for the target host via the control file:

<pxe>
  <pxe_localboot config:type="boolean">true</pxe_localboot>
  <pxelinux-config>
    DEFAULT linux
    LABEL linux
    localboot 0
  </pxelinux-config>
  <tftp-server>192.168.1.115</tftp-server>
  <pxelinux-dir>/pxelinux.cfg</pxelinux-dir>
  <filename>__MAC__</filename>
</pxe>

This entry will upload a new configuration for the target host to the TFTP server shortly before the first reboot happens. In most installations the TFTP daemon runs as user nobody. You need to make sure this user has write permissions to the pxelinux.cfg directory. You can also configure the file name that will be uploaded. If you use the magic __MAC__ file name, the file name will be the MAC address of your machine like, for example 01-08-00-27-79-49-ee. If the file name setting is missing, the IP address will be used for the file name.

To do another auto-installation on the same machine, you need to remove the file from the TFTP server.

6.3 Invoking the Auto-Installation Process

6.3.1 Command Line Options

Adding the command line variable autoyast causes linuxrc to start in automated mode. linuxrc searches for a configuration file, which should be distinguished from the main control file in the following places:

  • in the root directory of the initial RAM disk used for booting the system,

  • in the root directory of the boot medium

The configuration file used by linuxrc can have the following keywords (for a detailed description of how linuxrc works and other keywords, see Appendix C, Advanced Linuxrc Options):

Table 6.1: Keywords for linuxrc

Keyword

Value

autoupgrade

Initiate an automatic upgrade using AutoYaST, see Section 4.10, “Upgrade”. For some use cases, you need the autoyast parameter (see AutoYaST Control File Locations for details).

autoyast

Location of the control file for automatic installation, see AutoYaST Control File Locations for details.

autoyast2

Location of the control file for automatic installation. Similar to autoyast option but linuxrc parses the provided value and, for example, tries to configure a network when needed. For information about differences between the AutoYaST and linuxrc URI syntax, see the documentation of linuxrc. AutoYaST's rules and classes are not supported.

ifcfg

Configure and start the network. Required if the AutoYaST is to be fetched from a remote location. See Section C.3, “Advanced Network Setup” for details.

insmod

Kernel modules to load

install

Location of the installation directory, for example install=nfs://192.168.2.1/CDs/.

instmode

Installation mode, for example nfs, http etc. (not needed if install is set).

server

Server (NFS) to contact for source directory

serverdir

Directory on NFS Server

y2confirm

Even with <confirm>no</confirm> in the control file, the confirm proposal comes up.

These variables and keywords will bring the system up to the point where YaST can take over with the main control file. Currently, the source medium is automatically discovered, which in some cases makes it possible to initiate the auto-install process without giving any instructions to linuxrc.

The traditional linuxrc configuration file (info) has the function of giving the client enough information about the installation server and the location of the sources. Usually, this file is not required, but it is needed in special network environments where DHCP and BOOTP are not used or when special kernel modules need to be loaded.

All linuxrc keywords can be passed to linuxrc using the kernel command line. The command line can also be set when creating network bootable images or it can be passed to the kernel using a specially configured DHCP server in combination with Etherboot or PXE.

The command line variable autoyast can be used in the format described in the following list.

AutoYaST Control File Locations
Format of URIs

The autoyast syntax for the URIs for your control file locations can be confusing. The format is SCHEMA://HOST/PATH-TO-FILE. The number of forward slashes to use varies. For remote locations of your control file, the URI looks like this example for an NFS server, with two slashes: autoyast=nfs://SERVER/PATH.

It is different when your control file is on a local file system. For example, autoyast=usb:///profile.xml is the same as autoyast=usb://localhost/profile.xml. You may omit the local host name, but you must keep the third slash. autoyast=usb://profile.xml will fail because profile.xml is interpreted as the host name.

When no control file specification is needed

For upgrades, no autoyast variable is needed for an automated offline upgrade.

For new installations, autoyast will be started if a file named autoinst.xml is in one of the following three locations:

  1. The root directory of the installation flash disk (e.g. USB stick).

  2. The root directory of the installation medium.

  3. The root directory of the initial RAM disk used to boot the system.

autoyast=file:///PATH

Looks for control file in the specified path, relative to the source root directory, for example file:///autoinst.xml when the control file is in the top-level directory of any local file system, including mounted external devices such as a CD or USB drive. (This is the same as file://localhost/autoinst.xml.)

autoyast=device://DEVICE/FILENAME

Looks for the control file on a storage device. Do not specify the full path to the device, but the device name only (e.g. device://vda1/autoyast.xml). You may also omit specifying the device and trigger autoyast to search all devices, for example: autoyast=device://localhost/autoinst.xml, or autoyast=device:///autoinst.xml.

autoyast=nfs://SERVER/PATH

Looks for the control file on an NFS server.

autoyast=http://[user:password@]SERVER/PATH

Retrieves the control file from a Web server using the HTTP protocol. Specifying a user name and a password is optional.

autoyast=https://[user:password@]SERVER/PATH

Retrieves the control file from a Web server using HTTPS. Specifying a user name and a password is optional.

autoyast=tftp://SERVER/PATH

Retrieve the control file via TFTP.

autoyast=ftp://[user:password@]SERVER/PATH

Retrieve the control file via FTP. Specifying a user name and a password is optional.

autoyast=usb:///PATH

Retrieve the control file from USB devices (autoyast will search all connected USB devices).

autoyast=relurl://PATH

Retrieve the control file from the installation source: either from the default installation source or from the installation source defined in install=INSTALLATION_SOURCE_PATH.

autoyast=cifs://SERVER/PATH

Looks for the control file on a CIFS server.

autoyast=label://LABEL/PATH

Searches for a control file on a device with the specified label.

Several scenarios for auto-installation are possible using different types of infrastructure and source media. The simplest way is to use the source media (DVD number one) of SUSE Linux Enterprise Server. But to initiate the auto-installation process, the auto-installation command-line variable should be entered at system boot-up and the control file should be accessible for YaST.

In a scripting context, you can use a serial console for your virtual machine, that allows you to work in text mode. Then you can pass the needed parameters from an expect script or equivalent.

The following list of scenarios explains how the control file can be supplied:

Using the Original SUSE Linux Enterprise Server DVD-ROM

When using the original DVD-ROM (DVD #1 is needed), the control file needs to be accessible via flash disk or network:

Flash Disk.  Access the control file via the autoyast=usb://PATH option.

Network.  Access the control file via the following commands: autoyast=nfs://.., autoyast=ftp://.., autoyast=http://.., autoyast=https://.., autoyast=tftp://.., or autoyast=cifs://...

Using a Custom DVD-ROM

In this case, you can include the control file directly on the DVD-ROM. When placing it in the root directory and naming it autoinst.xml, it will automatically be found and used for the installation. Otherwise use autoyast=file:///PATH to specify the path to the control file.

When using a DVD-ROM for auto-installation, it is necessary to instruct the installer to use the DVD-ROM for installation instead of trying to find the installation files on the network. This can be done by adding the instmode=cd option to the kernel command line (this can be automated by adding the option to the isolinux.cfg file on the DVD).

Using a Network Installation Source

This option is the most important one because installations of multiple machines are usually done using SLP or NFS servers and other network services like BOOTP and DHCP. The easiest way to make the control file available is to place it in the root directory of the installation source naming it autoinst.xml. In this case it will automatically be found and used for the installation. The control file can also reside in the following places:

Flash Disk.  Access the control file via the autoyast=usb://PATH option.

Network.  Access the control file via the following commands: autoyast=nfs://.., autoyast=ftp://.., autoyast=http://.., autoyast=https://.., autoyast=tftp://.., or autoyast=cifs://...

Note
Note: Disabling Network and DHCP

To disable the network during installations where it is not needed or unavailable, for example when auto-installing from DVD-ROMs, use the linuxrc option netsetup=0 to disable the network setup.

Note
Note: Difference between the autoyast and autoyast2 Options

The options autoyast and autoyast2 are very similar but differ in one important point:

  • When you use autoyast=http://..., you need to provide linuxrc with the network configuration.

  • When you use autoyast2=http://..., linuxrc tries to configure the network for you.

If autoyast=default is defined, YaST will look for a file named autoinst.xml in the following three places:

  1. the root directory of the flash disk,

  2. the root directory of the installation medium,

  3. the root directory of the initial RAM disk used to boot the system.

With all AutoYaST invocation options, excluding default, it is possible to specify the location of the control file in the following ways:

  1. Specify the exact location of the control file:

    autoyast=http://192.168.1.1/control-files/client01.xml
  2. Specify a directory where several control files are located:

    autoyast=http://192.168.1.1/control-files/

    In this case the relevant control file is retrieved using the hex digit representation of the IP as described below.

If only the path prefix variable is defined, YaST will fetch the control file from the specified location in the following way:

  1. First, it will search for the control file using its own IP address in uppercase hexadecimal, for example 192.0.2.91 -> C000025B.

  2. If this file is not found, YaST will remove one hex digit and try again. This action is repeated until the file with the correct name is found. Ultimately, it will try looking for a file with the MAC address of the client as the file name (mac should have the following syntax: 0080C8F6484C) and if not found a file named default (in lowercase).

As an example, for 192.0.2.91, the HTTP client will try:

C000025B
C000025
C00002
C0000
C000
C00
C0
C
0080C8F6484C
default

in that order.

To determine the hex representation of the IP address of the client, use the utility called /usr/bin/gethostip available with the syslinux package.

Example 6.1: Determine HEX code for an IP address
# /usr/bin/gethostip 10.10.0.1
10.10.0.1 10.10.0.1 0A0A0001

6.3.2 Auto-installing a Single System

The easiest way to auto-install a system without any network connection is to use the original SUSE Linux Enterprise Server DVD-ROMs and a flash disk. You do not need to set up an installation server nor the network environment.

Create the control file and name it autoinst.xml. Copy the file autoinst.xml to the flash disk.

6.3.3 Combining the linuxrc info file with the AutoYaST control file

If you choose to pass information to linuxrc using the info file, it is possible to integrate the keywords in the XML control file. In this case the file needs to be accessible to linuxrc and needs to be named info.

Linuxrc will look for a string (start_linuxrc_conf in the control file which represents the beginning of the file. If it is found, it will parse the content starting from that string and will finish when the string end_linuxrc_conf is found. The options are stored in the control file in the following way:

Example 6.2: Linuxrc options in the control file
....
  <install>
....
    <init>
      <info_file>
<![CDATA[
#
# Do not remove the following line:
# start_linuxrc_conf
#
install: nfs://192.168.1.1/CDs/full-i386
textmode: 1
autoyast: file:///info

# end_linuxrc_conf
# Do not remove the above comment
#
]]>

      </info_file>
    </init>
......
  </install>
....

Note that the autoyast keyword must point to the same file. If it is on a flash disk, then the option usb:/// needs to be used. If the info file is stored in the initial RAM disk, the file:// option needs to be used.

6.4 System Configuration

The system configuration during auto-installation is the most important part of the whole process. As you have seen in the previous chapters, almost anything can be configured automatically on the target system. In addition to the pre-defined directives, you can always use post-scripts to change other things in the system. Additionally you can change any system variables, and if required, copy complete configuration files into the target system.

6.4.1 Post-Install and System Configuration

The post-installation and system configuration are initiated directly after the last package is installed on the target system and continue after the system has booted for the first time.

Before the system is booted for the first time, AutoYaST writes all data collected during installation and writes the boot loader in the specified location. In addition to these regular tasks, AutoYaST executes the chroot-scripts as specified in the control file. Note that these scripts are executed while the system is not yet mounted.

If a different kernel than the default is installed, a hard reboot will be required. A hard reboot can also be forced during auto-installation, independent of the installed kernel. Use the reboot property of the general resource (see Section 4.1, “General Options”).

6.4.2 System Customization

Most of the system customization is done in the second stage of the installation. If you require customization that cannot be done using AutoYaST resources, use post-install scripts for further modifications.

You can define an unlimited number of custom scripts in the control file, either by editing the control file or by using the configuration system.