In a disk system with 100 cylinders, the request to access the cylinder occur in following sequence: 34, 4, 7, 19, 10, 83, 2, 6, 20, 15. Assuming that the…
In a disk system with 100 cylinders, the request to access the cylinder occur in following sequence: 34, 4, 7, 19, 10, 83, 2, 6, 20, 15. Assuming that the head is currently at cylinder 50, then what is the time taken to satisfy all requests if it takes 1 second to move from one cylinder to another? (Shortest seek time first policy is used)
Show answerHide answer
Correct answer: (B) 129 seconds
Explanation
SSTF from 50: 34 (16), 20 (14), 19 (1), 15 (4), 10 (5), 7 (3), 6 (1), 4 (2), 2 (2), 83 (81). The total movement is 129 cylinders, so it takes 129 seconds.