The book is a great introduction to system design issues that are only taught at few courses in few universities. even-though they show up in computer systems everywhere. This is a very good and easy read for any one in computer industry . it describes all parts of computer systems and how they interact very well. The extension of the book is online and many chapters are available for free to download.
The chapter on Naming is worth the money of the book. I have not seen the discussion of naming in such detail and simple terms anywhere,
The authors are very well respected professors at MIT and have experience in operating systems and computer system since its early days.
I highly recommend this book to any hardware or software student or professional engnineer.