Question

Suppose that a disk drive has 5,000 cylinders, numbered 0 to 4,999. The drive is currently serving a request at cylinder 2,150, and the previous request was at cylinder 1,805. The queue of pending requests, in FIFO order, is:

Answer 1

Answer:

The queue pending requests of FIFO order is ;

86, 1470, 1774, 948, 1509, 1022, 1750, 130.

Explanation:

The FCFS schedule is 143, 86, 1470, 913, 1774, 948, 1509, 1022, 1750, 130.

Total seek distance is 7081.

The SSTF schedule is 143, 130, 86, 913, 948, 1022, 1470, 1509, 1750, 1774.

Total seek distance is 1745.

The LOOK schedule is 143, 913, 948, 1022, 1470, 1509, 1750, 1774, 130, 86.

Total seek distance is 3319.

The SCAN schedule is 143, 913, 948, 1022, 1470, 1509, 1750, 1774, 4999, 130, 86.

Total seek distance is 9769.