1.

Whenever a process needs I/O to or from a disk it issues a ______________

2.

If a process needs I/O to or from a disk, and if the drive or controller is busy then :

3.

Consider a disk queue with requests for I/O to blocks on cylinders :
98 183 37 122 14 124 65 67
Considering FCFS (first cum first served) scheduling, the total number of head movements is, if the disk head is initially at 53 :

4.

Consider a disk queue with requests for I/O to blocks on cylinders :
98 183 37 122 14 124 65 67
Considering SSTF (shortest seek time first) scheduling, the total number of head movements is, if the disk head is initially at 53 :

5.

Random access in magnetic tapes is _________ compared to magnetic disks.

6.

Magnetic tape drives can write data at a speed ________ disk drives.

7.

On media that use constant linear velocity (CLV), the _____________ is uniform.

8.

SSTF algorithm, like SJF __________ of some requests.

9.

In the ______ algorithm, the disk arm starts at one end of the disk and moves toward the other end, servicing requests till the other end of the disk. At the other end, the direction is reversed and servicing continues.

10.

In the _______ algorithm, the disk head moves from one end to the other , servicing requests along the way. When the head reaches the other end, it immediately returns to the beginning of the disk without servicing any requests on the return trip.

11.

In the ______ algorithm, the disk arm goes as far as the final request in each direction, then reverses direction immediately without going to the end of the disk.