Q.Consider the following disk request sequence for a disk with 100 tracks
98, 137, 122, 183, 14, 133, 65, 78. Head pointer starting at 54 and moving in left direction. Find the number of head movements in cylinders using SCAN scheduling.
(a)850(left)
(b)220(right)
(c)130(left)
(d)237(right)
ANSWER:
Question 2
Q.Consider a disk queue with requests for I/O to blocks on cylinders 98, 183, 41, 122, 14, 124, 65, 67. The SCAN scheduling algorithm is used. The head is initially at cylinder number 53 moving towards larger cylinder numbers on its servicing pass. The cylinders are numbered from 0 to 199. The total head movement (in number of cylinders) incurred while servicing these requests is _______.
(a)221
(b)331
(c)111
(d)110
ANSWER:
Question 3
Q.Disk contains 200 tracks. The request queue is 93, 176,42,148,27,14,180. Head position at 55. Calculate seek time.
(a)329(right)
(b)223(left)
(c)558(left)
(d)336(right)
ANSWER:
Question 4
Q.Disk contains 200 tracks. The request queue is 23, 89, 132, 42, 187. Head position at 100. Calculate seek time.
(a)986(right)
(b)556(left)
(c)332(right)
(d)287(left)
ANSWER:
Question 5
Suppose a disk is having 200 cylinders number from 0 to 199. Head is at 53. The request queue is 98,183,37,122,14,124,65,67. Calculate seek time.