Question

g Consider a disk queue with requests for I/O to blocks on cylinders 95, 120, 41, 122, 15, 142, 65, 167. The Shortest Seek Time First (SSTF) scheduling algorithm is used. The head is initially at cylinder number 100. The cylinders are numbered from 0 (center of disk) to 199 (edge of disk). a) List the requests in the order in which they will be serviced. b) What is the total head movement (in number of cylinders) incurred while servicing these requests

Answer 1

Answer:

follows are the solution to the given question:

Explanation:

Please find the image file for the SSTF scheduling algorithm.

Following are the requested order:

$Request \ \ order :\\\\95\\120\\122\\142\\167\\65\\ 41\\15$

Calculating the Total Head Movement:

$= (100-95) + (120-95) + (122-120) + (142-122) + (167-142) + (167-65) + (65-41) + (41-15)\\\\= 5 + 25 + 2 + 20 + 25 + 102 + 24 + 26\\\\= 229$