Marc,
Try the following documentation which covers the main guides for
Project Server 2003. As a quick answer, there are two services which
you can move to other servers to help Project Server scale. These are
the Views Notifications service and the Sessions Management service.
Views Notifications is responsible for processing (updating) views when
you publish a project or build an OLAP cube. Sessions Management keeps
track of all of the different sessions connected to Project Server. In
a standard installation these are put on the same machine with Project
Server. If you want to move these to different machines, you will need
to install the services to other machines before you install Project
Server. Finally, if you want to setup Project Server on an IIS
load-balanced cluster, you will need to move the services to another
machine or machines. Those two services cannot be installed on as part
of an active cluster, only active-passive. And if you put them on an
active-passive cluster, it is a manual process to update the registry
of Project Server to point to the backup server running the process.
Microsoft Office Project Server 2003 Configuration Planning Guide
http://go.microsoft.com/fwlink/?LinkID=20235
.. Microsoft Office Project Server 2003 Disaster Recovery Guide
http://go.microsoft.com/fwlink/?LinkID=20234
.. Microsoft Office Project Server 2003 Installation Guide
http://go.microsoft.com/fwlink/?LinkID=20233
.. Microsoft Office Project Server 2003 Application Configuration Guide
http://go.microsoft.com/fwlink/?LinkID=20237
.. Microsoft Office Project Server 2003 Administrator's Guide
http://go.microsoft.com/fwlink/?LinkID=20236
David