Disk scheduling: In a computer, multiple processes run over the same time. To handle this multiple processes, the operating system decides which process has to be executed first. This technique is called as disk scheduling. There are different types of scheduling algorithms. They are as follows: First-come, First-served (FCFS) Shortest-Seek-Time-First (SSTF) SCAN SCAN disk scheduling algorithm : The SCAN algorithm is called as elevator algorithm. In the SCAN algorithm, the disk arm starts at one end of the disk and moves toward the other end. It processes the request for each cylinder until it gets to the other end of the disk. At the other end, it reverses the direction of head movement. The head continuously moves back and forth across the disk based upon the closest distance.

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Chapter 11, Problem 56E

Program Plan Intro

Disk scheduling:

In a computer, multiple processes run over the same time.

To handle this multiple processes, the operating system decides which process has to be executed first. This technique is called as disk scheduling.

There are different types of scheduling algorithms. They are as follows:

First-come, First-served (FCFS)

Shortest-Seek-Time-First (SSTF)

SCAN

SCAN disk scheduling algorithm:

The SCAN algorithm is called as elevator algorithm.

In the SCAN algorithm, the disk arm starts at one end of the disk and moves toward the other end.

It processes the request for each cylinder until it gets to the other end of the disk.

At the other end, it reverses the direction of head movement.

The head continuously moves back and forth across the disk based upon the closest distance.

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