Plan 9: The next Generation

Dr. Hans-Peter Bischof
Department of Computer Science
SUNY Oswego

What is Plan 9?

In the late 1980's, the Computer Science Research Center of Bell Labs began developing a new and innovative operating system named Plan 9. The operating system was named after the movie 'Plan 9 From Outer Space' directed by James Wood Jr.

Plan 9 is a new, distributed computer operating system with associated utilities. In the most general configuration, it uses three kinds of components:

- terminals that sit on users' desks,
- file servers that store permanent data, and
- CPU servers that provide faster CPUs, user authentication, and network gateways.

The key ideas of the system are:

1. All the system objects present themselves as named files that are manipulated by read/write operations.
2. All these files may exist either locally or remotely, and respond to a standard protocol -- 9P.
3. The file system namespace, the set of objects visible to a program, is dynamically and individually adjustable for each of the programs running on a particular machine.

This talk will give an introduction into Plan 9 and a description on which topic I was working.

I developed two technologies which enable us to take a look inside a running operating system, this makes it easier to understand what is going on inside an OS.

1. A programmable kernel device (kernel server), which accepts a program in a special language, interpretes the code and changes the functionality of the kernel during runtime, collects the generated data and provides an interface for the collected data. I used specialized animation programs for the animation of the data. We use this technique for a controlled look inside a closed system.

2. With the same strategy as inserting a tee inside a Unix-shell pipeline we can track and modify the protocol stream between servers -- file server, ram filesystem server -- and kernel. The tee receives the protocol messages from the kernel, displays them for modification and sends the resulting messages to the intended server. In the same way the tee transmits the replies of the server.

Full notes of the talk are available.

Colloquia Series page.