FCFS disk scheduling in Operating Systems - Mini Project: Build & Apply

FCFS Disk Scheduling Simulation

📖 Scenario: You are managing a computer's disk drive. The disk head moves to read data from different tracks on the disk. The requests come in a certain order, and you want to simulate how the disk head moves using the First-Come, First-Served (FCFS) scheduling method.

🎯 Goal: Build a simple step-by-step simulation of the FCFS disk scheduling algorithm. You will create the list of disk requests, set the initial head position, calculate the total head movement as the disk head moves to each requested track in order, and finally complete the simulation by showing the total movement.

📋 What You'll Learn

Create a list called requests with the exact disk track numbers: 98, 183, 37, 122, 14, 124, 65, 67

Create a variable called head with the initial disk head position set to 53

Use a variable called total_movement to keep track of the total distance the disk head moves

Use a for loop with variables request to iterate over requests in order

Calculate the absolute distance between the current head position and the request, add it to total_movement, then update head to the request

At the end, have a variable called result that stores the total head movement as an integer

💡 Why This Matters

🌍 Real World

Disk scheduling algorithms help operating systems decide the order to access data on a hard drive, improving speed and efficiency.

💼 Career

Understanding disk scheduling is important for roles in system administration, operating system development, and performance optimization.

1

Create the list of disk requests

Create a list called requests with these exact disk track numbers in order: 98, 183, 37, 122, 14, 124, 65, 67

Operating Systems

# Create the list of disk requests
# Your code here

Need a hint?

Use square brackets [] to create a list and separate the numbers with commas.

2

Set the initial disk head position

Create a variable called head and set it to the initial disk head position 53

Operating Systems

requests = [98, 183, 37, 122, 14, 124, 65, 67]
# Set the initial disk head position
# Your code here

Need a hint?

Use a simple assignment to create the variable head with the value 53.

3

Calculate total head movement using FCFS

Create a variable called total_movement and set it to 0. Then use a for loop with variable request to iterate over requests. Inside the loop, calculate the absolute distance between head and request, add it to total_movement, and update head to request

Operating Systems

requests = [98, 183, 37, 122, 14, 124, 65, 67]
head = 53
# Calculate total head movement
# Your code here

Need a hint?

Use abs() to get the absolute difference between two numbers.

4

Store the final total head movement

Create a variable called result and set it equal to total_movement to store the total distance the disk head moved

Operating Systems

requests = [98, 183, 37, 122, 14, 124, 65, 67]
head = 53
total_movement = 0
for request in requests:
    total_movement += abs(head - request)
    head = request
# Store the final total head movement
# Your code here

Need a hint?

Simply assign result to the value of total_movement.