Interview with Andrew Tanenbaum, Creator of MINIX

I recently had the opportunity to interview Andrew S. Tanenbaum, creator of the extremely secure Unix-like operating sytem MINIX 3. Andrew is also the author of Operating Systems Design and Implementation, the must-have book on programming and designing operating systems, and the man whose work inspired Linus Torvalds to create Linux. He has published over 120 works on computers (that's including manuals, second and third editions, and translations), and his works are known all over the world, being translated into a variety of different languages for educational use universally. He is currently a professor of computer science at Vrije University in Amsterdam, the Netherlands.

The following is my interview with Andrew Tanenbaum. I would like to thank him for taking time out of his busy schedule to answer my questions.

When and how did you first get into computer programming and operating system design?
I have been programming since I was at MIT as an undergraduate. Operating system design happened much later, in the 1980s, first with Amoeba, an experimental distributed operating system, then in 1984 with MINIX.

What influenced you to start developing MINIX?
I was teaching a course using UNIX V6 and then AT&T changed the license forbidding people from teaching it courses, the stupidest thing they could have done. They should have paid bounties to people teaching it in courses. I guess their attitude was "The fewer people who know about UNIX,
the better." At that point I decided if I wanted a UNIX-like system to teach, I'd have to write one myself. So I did.

Have your students ever helped you in the development of MINIX?
In the beginning, no. I wrote V1 entirely alone. Later on, many students had ideas and wrote code. I also got funding to hire some students to write code.

What made you decide to make MINIX based on a microkernel rather than a monolithic kernel?
Good software engineering principles dictate that your programs are modular. You don't want a bug in one piece to bring down the whole thing if that can be avoided. A microkernel is much better engineered and is more modular and easier to understand. Monolithic kernels are still too big
and unreliable. My metric is the TV set. The system should run for 10 years with a total of zero failures for 99.9% of the users.

Do you believe that there are certain drawbacks to making MINIX POSIX-compliant?
Not really.

Are there any drawbacks to running device drivers as separate user-mode processes?
There is a small performance penalty. We haven't really focused on performance, but the L4 people have shown the overhead for a microkernel can be reduced to 5-10%

Will MINIX ever have a windowing system besides X11, or is X11 stable and functional enough for MINIX?
Never say never, but X11 seems pretty good to me. I believe it is the only windowing system on Linux.

How well does MINIX run on dual-processor machines? Will MINIX ever be optimized for these types of computers?
We are just starting to work on multicore. It is MUCH harder than single core. I expect all multicore software to be riddled with errors.

Do you expect a lot of Linux users to switch over to MINIX?
Probably not.

What other projects have you been working on besides MINIX?
I have been involved with work on RFID security and privacy. See www.rfidvirus.org and www.rfidguardian.org.

What can we expect to see developed for MINIX in the future?
We are adding some missing features now like virtual memory and USB support, but the focus of the research is very high reliability and self healing.

If Linux's Tux penguin and MINIX's raccoon faced off in a fight to the death, who would win?
Raccoons are quite aggressive. Penguins are not. There would be chicken for dinner.

Andrew Tanenbaum can be contacted through a variety of ways listed at his website, www.cs.vu.nl/~ast/.

Matthew Mikolay (matt.mik<AT SYMBOL>hotmail.com) is a software developer and student in New Jersey. He has interests in open source software, Linux, and security.

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Comments

Penguins are not aggressive? Spoken like a mackerel with a short life expectancy. And just how long can a raccoon tread water?

RamboTribble

August 12, 2008

7:20 AM PT