Automating Linux Installations
An automated installation service is being used to install the Linux farms in the CERN computing centre and part of the desktop systems since end of 1998. The system is based on the Kickstart software. The configurations for 370 systems are currently registered. The system has been adapted to automatically install CERN's Standard Unix Environment (SUE). A number of Kickstart problems have been solved or circumvented. Work is currently done on a more general system suitable for desktop ?PCs.
Linux is becoming a key operating system at CERN. Some 900 PC's running Linux are currently installed on the site, and some 50 new machines are added monthly. A big percentage are part of data processing farms placed at CERN's computing centre, the rest being used as servers or desktop workstations. With the freezing of other ?UNIXes and the data and CPU requirements imposed by new experiments like COMPASS and specially LHC's, the amount of Linux PC's is expected to increase dramatically over the next years. Several problems will have to be overcomed, one being the system installation. A typical Linux installation takes around 20 minutes and requires human intervention in order to enter configuration data and monitor the execution. This is too inefficient and error prone with hundreds or even thousands of systems to install or reinstall. An automated procedure should therefore be used.
An automated installation procedure should fulfill several conditions, namely:
* unattended run: Installations should be run without (or minimal) human interaction. * concurrent installations: Multiple systems can be installed in parallel. * scalable: New clients (and OS releases) can be integrated easily. * flexible: A feature-rich configuration should be offered. * customisable: It should be possible to adapt the system to a specific environment and settings.
Kickstart is the automated installation method for Redhat and Fedora Linux distributions. A system administrator creates a file (called a Kickstart file) which describes the configuration and the required setup.
This file contains the required disk partition setup, the packages to be installed and other configuration items like the language, time zone, mouse and keyboard setup etc.
A Kickstart file may also contain a post installation procedure, in which a list of shell level commands may be specified which are executed once the normal installation process has finished.
The target machine is bootstrapped with a down sized kernel and a minimised root file system, the installation server is then NFS-mounted. The installation program starts and is driven by the contents of the Kickstart file.
The Kickstart file may be stored on the installation diskette or in a central repository accessed using the network via BOOTP and NFS. Often, a single Kickstart file can be used for installing multiple machines with similar configuration.