Disk requests are received by a disk drive for cylinders 5, 25, 18, 3, 39, 8 and 35 in that order. A seek takes 5 m sec per cylinder moved. How much seek time is needed to serve these requests for a Shortest Seek First (SSF) algorithm ? Assume that the arm is at cylinder 20 when the last of these requests is made with none of the requests yet served
| A. | 125 msec |
| B. | 295msec |
| C. | 575 msec |
| D. | 750 msec |
Answer : B Explanation : Shortest Seek Time First - minimizes arm movement Order to be followed is - (20) , 18,25,35,39, 8,5,3 Seek = 2+5+7+10+4+31+3+2 = 59 cylinders , 295 ms
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Option: A Explanation : Explanation will come here. Explanation will come here. Explanation will come here. Explanation will come here. Explanation will come here. |
