Red Hat System Administration II

Objectives

After completing this section, students should be able to:

Kickstart installation steps

An ordered process is required to automate the successful installation of Red Hat Enterprise Linux.

Three steps must be taken to perform a Kickstart installation:

Creating a Kickstart configuration file

There are two ways to create a Kickstart configuration file:

The system-config-kickstart utility presents a number of graphical dialog boxes, takes inputs from the user, then creates a text file with Kickstart directives that correspond to the user's choices. Each dialog box corresponds to a category of questions asked by the Red Hat installer, Anaconda. Optionally, an existing configuration file can be passed as an argument and system-config-kickstart will use it to populate values for configuration options. system-config-kickstart is provided by the system-config-kickstart package.

Figure 1.1: Configuring storage with system-config-kickstart

Creating a Kickstart configuration file from scratch with a text editor is rare. The Anaconda installer creates a file called /root/anaconda-ks.cfg that contains the Kickstart directives that can be used to generate the freshly installed system. This file makes a good starting point when creating a Kickstart configuration file with a text editor.

The following are some reasons for creating a Kickstart file manually instead of using system-config-kickstart:

ksvalidator is a utility that checks for syntax errors in a Kickstart configuration file. It will ensure keywords and options are properly used, but it will not validate URL paths, individual packages, or groups, nor any part of %post or %pre scripts. For instance, if the firewall --disabled directive is misspelled, ksvalidator could produce one of the following errors:

[student@desktopX]$ ksvalidator /tmp/anaconda-ks.cfg
The following problem occurred on line 10 of the kickstart file:
 
Unknown command: frewall
 
[student@desktopX]$ ksvalidator /tmp/anaconda-ks.cfg
The following problem occurred on line 10 of the kickstart file:
 
no such option: --dsabled

The pykickstart RPM provides ksvalidator.

Publish the Kickstart configuration file to Anaconda

Make the Kickstart configuration file available to the installer:

The installer must be able to access the Kickstart file to begin an automated installation. Although there are several methods to make the Kickstart configuration file available, the most common is through a network server such as an FTP server, a web server, or an NFS server. Network servers facilitate Kickstart file maintenance because changes only need to be made once and take effect immediately.

Providing Kickstart files on USB or CD-ROM is another convenient way to publish configuration files. The Kickstart configuration file is embedded on the boot media used to start the installation. When changes are made, new installation media must be generated.

It is possible to provide the Kickstart file on a local disk. This allows a quick way to rebuild a development server.

Boot Anaconda and point it to the Kickstart configuration file

Once a Kickstart method is chosen, the installer must be told where the Kickstart file is located. This is done by passing a ks=LOCATION argument to the installation kernel. The following are some sample specifications:

Figure 1.2: Specifying the Kickstart file location during PXE boot

For virtual machine installations using the Virtual Machine Manager or virt-manager, the Kickstart URL can be specified in a box under URL Options. When installing physical machines, boot using installation media and press the Tab key to interrupt the boot process. Enter one of the ks= entries above as a parameter to the installation kernel.