BCA Semester 4 – Operating System – Unit 6: Input/Output Device Management (4Hrs.)

Define the term seek time and rotational delay in disk scheduling. Suppose that a disk has 100 cylinders, numbered 0 to 99. The drive is currently serving a request at cylinder 43 and previous request was at cylinder 25.The queue of pending request, in FIFO order is: 86, 70, 13, 74, 48, 9, 22, 50, 30 Starting from the current head position, what is total distance (in cylinders) that the disk arm moves to satisfy all pending request for each of following disk scheduling algorithms?
a) FCFS
b) SSTF
c) SCAN
d) LOOK

Suppose that a disk has 200 cylinders (0-200). The head pointer is currently at 50 and previously at 35. The queue of pending request, in FIFO order is: 60, 190, 40, 125, 15, and 150. The time required to move per cylinder is 6 msec. Starting from the current head position, what is the total seek time needed to satisfy all the pending request for each of the following disk scheduling algorithms?
a) FCFS  b) SCAN

When programmed I/O is suitable than other I/O handling techniques? Explain different type System Threat.

What is Disk Access Time and Disk Response Time? Suppose that a disk has 200 cylinders, numbered $(0-199)$. The drive is currently serving a request at cylinder 43/and previous request was at cylinder 25. The queue of pending request, in FIFO order is: $55, 58, 39, 18, 90, 160, 150, 38, 184.$ Starting from the current head position, what is total distance (in cylinders) that the disk arm moves to satisfy all pending request for each of following disk scheduling algorithms?
a) FCFS
b) SSTF
c) C-SCAN
d) LOOK

What is Disk Access Time and Disk Response Time? Suppose that a disk has 200 cylinders, numbered (0-199). The drive is currently serving a request at cylinder 43/and previous request was at cylinder 25. The queue of pending request, in FIFO order is:$55, 58, 39, 18, 90, 160, 150, 38, 184.$ Starting from the current head position, what is total distance (in cylinders) that the disk arm moves to satisfy all pending request for each of following disk scheduling algorithms?
a) FCFS
b) SSTF
c) C-SCAN
d) LOOK

What is use of DMA controller? Consider the following process and answer the following questions.