A disk system has 100 cylinders, numbered 0 to 99. Assume that the read / write head is at cylinder 50 and determine the order of head movement for each algorithm to satisfy the following stream of requests. For comparison purposes, calculate the total head travel distance. They are listed in the order received. 40, 12, 22, 66, 67, 33, 80, 75, 85, 65, 8
A disk system has 200 cylinders, numbered 0 to 199. Assume that the read / write head is at cylinder 100 and determine the order of head movement for each algorithm to satisfy the following stream of requests received in the following order 23, 89, 132, 42, 187, 95, 180, 34, 119, 11, 123, and 64. Also calculate the total head travel distance.
Suppose a disk has 200 cylinders, numbered from 0 to 199. At some time the disk arm is at cylinder 53 and previous access was at 26. Given a queue of disk access requests for cylinders 30, 185, 90, 100, 45, 20, 110, 90, 10, 135, 70 and 145, discuss the sequence in which the requests are satisfied for various scheduling algorithms.
Suppose a disk has 200 cylinders, numbered from 0 to 199. At some time the disk arm is at cylinder 63 and previous access was at 176. Given a queue of disk access requests for cylinders 100, 175, 51, 133, 78, 140, 110, 90, 45, 135, 70 and 145, discuss the sequence in which the requests are satisfied for various scheduling algorithms.
Consider a disk queue with requests for I/O to blocks on cylinders 98, 183, 37, 122, 14, 124, 65, 67. If the disk head starts at 53, find the total head movement with respect to FCFS, SSTF, SCAN, C–SCAN and LOOK scheduling.
Perform FCFS, SSTF, SCAN algorithms for the following set of requests – 10, 22, 20, 2, 40, 6, 38 and calculate the average seek time. Arm is initially at cylinder 20 and maximum numbers of cylinders are 50.
Assume the head of a moving disk with 200 tracks, numbered 0 … 199, is currently serving a request at track 92, and has just finished a request at track 85 and the queue request is kept in the FIFO order, 109, 148, 89, 72, 126 and 142. What is the total head movement needed to satisfy these requests for the SCAN, C–SCAN, LOOK and C–LOOK disk scheduling algorithms.
A disk drive has 5000 cylinders numbered 0 to 4999. The drive is currently serving a request at cylinder 143, and the previous request was at cylinder 125. The queue of pending requests in FIFO order is 86, 1470, 913, 1774, 948, 1509, 1022, 1750, 130. Starting from the current head position, what is the total distance (in cylinders) that the disk arm moves to satisfy all the pending requests for each of the following disk scheduling algorithms – FCFS, SSTF, LOOK AND C–SCAN.
On a disk with 200 cylinders, numbered 0 to 199, compute the number of tracks the disk arm must move to satisfy the entire request in the disk queue. Assume the last request received was at track 100. The queue in FIFO order contains requests for the following tracks. 55, 58, 39, 18, 90, 160, 150, 38, 184. Perform the computation to find the seek time for the following disk scheduling algorithms: FCFS, SSTF, SCAN, C-SCAN, LOOK AND C-LOOK
Suppose that a disk drive has 3000 cylinders, numbered from 0 to 2999. The drive is currently serving a request at cylinder 14, and the previous request was at cylinder 115. The queue of pending requests, in FIFO order is 98, 1270, 923, 1674, 848, 1509, 1022, 1760, 120 starting from the current head position, what is the total distance (in cylinders) that the disk arm moves to satisfy all the pending requests for each of the disk scheduling algorithms.
