Professor: Welcome to this book! It's called Operating Systems in Three Easy Pieces, and I am here to teach you the things you need to know about operating systems. I am called "Professor" who are you?
Student: Hi Professor I am called "Student", as you might have guessed. And I am here and ready to learn!
Professor: Sounds good. Any questions?
Student: Sure! Why is it called "Three Easy Pieces"?
Professor: That's an easy one. Well, you see, there are these great lectures on Physics by Richard Feynman...
Student: Ol! The guy who wrote "Surely You're Joking, Mr. Feynman", right? Great booki Is this going to be itilarious like that book was?
Professor: Lim... well, no. That book was great, and I'm glad you've read it. Hopefully this book is more like his notes on Physics. Some of the basics were summed up in a book called "Six Easy Pieces". He was talking about Physics; we're going to do Three Easy Pieces on the fine topic of Operating Systems. This is appropriate, as Operating Systems are about half as hard as Physics
Student: Well, I liked physics, so that is probably good. What are those pieces?
Professor: They are the three key ideas we're going to learn about: virtualiza-
tion, concurrency, and persistence. In learning about these ideas, we'll learn all about how an operating system works, including how it decides what program to run next on a CPU, how it handles memory overload in a virtual memory sys tem, how virtual machine monitors work, how to manage information on disks, and even a little about how to build a distributed system that works when parts have failed. That sort of stuff
Student: I have no idea what you're talking about, really.
Professor: Good! That means you are in the right class.
Student: I have another question : what's the best way to learn this stuff?
Professor: Excellent query! Well, each person needs to figure this out on their own, of course, but here is what I would do: go to class, to hear the professor introduce the material. Then, at the end of every week, read these notes, to help the ideas sink into your head a bit better. Of course, some time later (hint: before the exam!), read the notes again to firm up your knowledge. Of course, your pro- fessor will no doubt assign some homeworks and projects, so you should do thos in particular, doing projects where you write real code to solve real problems is the best way to put the ideas within these notes into action. As Confaches said...
Student: Oh, I know! I hear and I forget. I see and I remember. I do and I understand. Or something like that.
Professor (surprised) How did you know what I was going to say?!
Student: It seemed to follow. Also, I am a big fan of Confucius, and an even bigger fan of Xunzi, who actually is a better source for this quote
Professor (stunned) Well, I think we are going to get along just fine! just fine indeed.
Student: Professor just one more question, if I may What are these dialogues for? I mean, isn't this just supposed to be a book? Why not present the material directly?
Professor: Ah, good question, good question! Well, I think it is sometimes useful to pull yourself outside of a narrative and think a bit; these dialogues are those times. So you and I are going to work together to make sense of all of these pretty complex ideas, Are you up for it?
Student: So are force to think? Well, I'm up for that. I mean, what else do I have to do anyhow? It's not like I have much of a life outside of this book.
Professor Me neither, sadly. So let's get to work!
