Disk requests are received... cylinder 5, 25, 18, 3, 39, 8, 35. Head at 20. SSF algorithm. Total seek?
- A. 125 msec
- B. 295 msec
- C. 575 msec
- D. 750 msec
Answer: A. 125 msec
Explanation: Current 20. Queue: 3, 5, 8, 18, 25, 35, 39. Order: 18 (diff 2), 25 (diff 7), 35 (diff 10), 39 (diff 4), 8 (diff 31), 5 (diff 3), 3 (diff 2). Path: 20->18->25->35->39->8->5->3. Distance: 2+7+10+4+31+3+2 = 59 cylinders? Wait. SSF from 20: 18 (dist 2). From 18: 25(7) or 8(10)? 25. From 25: 35(10) or 8(17)? 35. From 35: 39(4). From 39: 8(31). From 8: 5(3). From 5: 3(2). Total: 2+7+10+4+31+3+2 = 59. Options are much higher. Maybe missing scaling factor or 'msec' implies time calculation. If 1 cylinder = x msec?