This document describes how to construct an Access Grid node using only the Linux operating system. This construction method has been used for two separate nodes at the University of Sydney and have now been in operation for nearly two years. The first of these, a three machine node, was used for our participation in the SCGlobal 2001 event. A single machine version was built soon after. This method of construction has since been successfully implemented by another six sites throughout Australia.

The method of construction described here relates to Access Grid nodes prior to the AG2 release of May, 2003. It is similar to the AG2 version in that the primary services (video, audio, MUD) may be configured to run on any of the machines in the node. However the AG2 version is far more advanced especially in terms of dynamic configurability, authentication and deployment of new services.

The typical Access Grid node, built to the recipe provided by the Access Grid team at Argonne National Laboratory, uses a mixture of Windows and Linux machines. An excellent AGDP Guide Building an Access Grid Node provides the information required to build such a system. Probably all of the information in that Guide that doesn't relate to actual node machines also applies to the system decribed here. For instance, room construction will not depend on the operating system(s) being used.

A particular benefit of using this method is its scalability. Exactly the same method of construction may be used to implement nodes comprising any number of machines. The normal distinction between display, video and audio machines is largely unimportant, since each machine participating in a node is merely a provider of arbitrary services, in particular the video, audio and MUD functions used in an AG node. All these functions can be performed on a single machine or shared between a number of machines built in the same way.

An issue arising from this method of construction is that of applications designed particularly for a non-Linux environment, in particular Distributed PowerPoint and Gentner (Clear One) control software. In the short term our solution has been to have a separate Windows machine available to run these applications. In practice this works very well. For large events in particular, the functions of presentation and node operation are best separated anyway. The Genter control software is rarely used, the settings rarely being changed after optimal settings have been made. In the longer term, it is expected that versions these applications will run in a Linux environment.