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DRAFT 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 M. Gribaudo, R.Mirandola 25-07-2016 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 for the multiple-choice part: correct answers +1 point, unanswered questions 0 points, wrong answers -0.333 points. You cannot keep a copy of the exam when you leave the room. y For your examination, preferably print documents compiled from auto-multiple-choice. y DRAFT y +1/2/59+ y Disks noindent A HDD has a rotation speed of6000 RPM, an average seek time of 3 ms, a negligi- ble controller overhead and transfer time of128 MB/s. Files are stored into blocks whose size is4 KB. Question 1 The rotational latency of the disk is: A 6 ms B 5 ms C 10 ms D 3 ms SOLUTION: The rotational latency is half of the time required to perform one rotation: Tl = 60000 2·6000 = 5 ms. Question 2 The average time required to read a4 KB block is: A 8.0305 ms B 8.2441 ms C 13.0305 ms D 13.244 ms SOLUTION: The total average transfer time is: Ta =Tl +Ts +F/rt = 5 + 3 + 4/(128∗ 1024)∗ 1000 = 8.0305 ms Question 3 The time required…