The disadvantage to Guardian’s naming system was that it was overcomplicated, inconsistent, and all around sucked. There were no advantages to it.
I’ve never worked on a system that has needed much fault tolerance. However, when reading the section about the messaging system, it reminded me immensely of the good things that I’ve heard about Erlang leading to very reliable systems due to its message passing style of communication.
Guardian was terribly insecure.
Guardian’s checkpoint system seemed terrible for several reasons. It struck me as a huge flaw that the programmer had to explicitly invoke checkpoints. A decent system should hide that. If it forces you to do this manually, you think that would remove some overhead so that the system could perform well.
I thought it was very interesting that EXPAND and FOX allowed the system to scale to more processors with trivial ease, though apparently the performance gains were not quite what you would expect.
Overall, this chapter was a big waste of time. The book is named “Beautiful Architecture,” not “Grotesque Architecture.” There was very little to take away other than the fact that this OS failed because it was poorly designed. No good lessons, though.