The following components comprise Oracle Parallel Server:

there si no seprate cd as such it all dependents on your liscence option.

Component Description
Oracle8i Enterprise Edition
Provides the applications and files to manage a database. All other Oracle Parallel Server components are layered on top of Oracle8i Enterprise Edition.

Oracle Parallel Server Option
Provides the necessary Oracle Parallel Server scripts, initialization files, and data files.

Oracle Parallel Server Management
Provides a single point for starting, stopping, and monitoring the activity of parallel servers and parallel server instances from within Oracle Enterprise Manager Console.

See Chapter 5, "Installing and Configuring Oracle Parallel Server Management" and Chapter 6, "Administering Oracle Parallel Server".

Operating System Dependent layer
Consists of several software components developed by vendors. The Operating System Dependent layer maps the key OS/cluster-ware services required for proper operation of Oracle Parallel Server.

at this moment i am not sure about clustered servers hope somebody here gets back to you on that.or maybe i will do that sometime later :-)