Overall this books covers the exam material adequately enough, but is no substitute for memorizing the commands and reading the man pages therein. Unfortunately this exam covers some antiquated tech for purposes of maintenance support etc, and from a software engineers perspective is therefore not very applicable to normal day-to-day operations. The quizzes at the end of the chapter are challenging enough and from a systems engineer or more aptly a devops or SRE this sets a good foundation to build from. My page tabs are on 13, 61, 80, 103, 142-143, 203, 221, 295 & 455.