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y +1/1/60+ y Student ID ( Matricola) 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 Computing Infrastructures Course 095897 P. Cremonesi, M. Roveri Example exam Last Name / Cognome: ................................................................. First Name / Nome: ................................................................. Answers must be given exclusively on the answer sheet (last sheet): DO NOT FILL ANY BOX IN THIS SHEET Students must use pen (black or blue) to mark answers (no pencil). Students are permitted to use a non-programmable calculator. Students are NOT permitted to copy anyone else’s answers, pass notes amongst themselves, or engage in other forms of misconduct at any time during the exam. Students are NOT permitted to use mobile phones and similar connected devices. Scores: correct answers +1.5 point, unanswered questions 0 points, wrong answers -0.5 points. Questions will multiple answers will be considered as not answered (0 points). y y y +1/2/59+ y Question 1 Which module is not typically present in the racks of a DataCenter? A Servers B Storage units C Power distribution units D Embedded systems Question 2 One of these configurations is not considered in Data-center network architectures. Which one? A D-Cell B Fat-tree C Direct Connection D Three layers In the following questions we will assume that both failure and repair events follow exponential distributions. Question 3 Consider a system built by two di fferent components in parallel. Assume for component A: MTTF A = 121 days and MTTR A =9 days and for component B: MTTF B = 282 days and MTTR B = 12 days. The availability of the whole system is equal to: A 0.997174 B 0.892775 C None of the oth- ers D 0.944975…