I decided to not build the last two xen boxes in chapter 3. So far the book has been a major disappointment. The author wasn't even trying in chapter 3. And I really wonder if the reviewers read the book.
Whole steps were left out while installing the NetBSD box, and instead of giving pointers to make things work during install, it was a case of oh just go read this web page on the NetBSD site.
Overall I'm very disappointed with the book.