Question

Consider the following information: ✓ A disk drive with 200 cylinders, ✓ A request queue : 98, 149, 37, 122, 14, 124, 65, 67 ✓ Head pointer 25. ✓ Direction: the disk arm is moving to innermost. Answer the following questions. (a) By using the C-LOOK disk scheduling algorithms, illustrates by drawing the movement of the disk arm to satisfy the requests. Label clearly. (b) Calculate the total distance (in cylinders) that the disk arm moves to satisfy the requests. Show your working. (C) If the LOOK disk scheduling algorithms is used, briefly describe a conclusion that can be made about the disk arm movement to satisfy the requests.

Answer 1

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Look Disk Scheduling Algonithm moves into a In Look algonithm, the dish particular its path and request coming end the in duection and senvices the aften reaching OF nequest ( maximum requested cylinder) ,it direction and the nequest amiving its path so algonitum the minimum requested cyulinda (i.e nequested cylinda the traverse direction revenge its again senvice this fu goes only to last in 0 14 25 65 67 98 100 122 128 199 37 6 S 67 98 149 124 Total Distance (19-9-25) + (299-14) = 124 + 135 259 Any C LOOK Look have same In above example, both and efficiency Total Distance (look) = Total Distance Clook