LOOK and C-LOOK variants in Operating Systems - Mini Project: Build & Apply

Understanding LOOK and C-LOOK Disk Scheduling Algorithms

📖 Scenario: You are working as a system administrator managing disk operations. You want to understand how the LOOK and C-LOOK disk scheduling algorithms work to optimize disk head movement and reduce waiting time.

🎯 Goal: Build a step-by-step explanation and example of how the LOOK and C-LOOK algorithms schedule disk requests, showing the order in which disk requests are serviced.

📋 What You'll Learn

Create a list of disk requests with exact values

Set the initial position of the disk head

Explain the LOOK algorithm by ordering requests based on head movement

Explain the C-LOOK algorithm by ordering requests with circular scanning

💡 Why This Matters

🌍 Real World

Disk scheduling algorithms like LOOK and C-LOOK help operating systems manage how the disk head moves to read or write data efficiently, reducing wait times and improving performance.

💼 Career

Understanding these algorithms is important for roles in system administration, operating system development, and performance optimization.

1

DATA SETUP: Create the list of disk requests

Create a list called disk_requests with these exact integer values: 95, 180, 34, 119, 11, 123, 62, 64.

Operating Systems

# Create the list of disk requests
# Your code here

Need a hint?

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

2

CONFIGURATION: Set the initial disk head position

Create a variable called head_position and set it to the integer 50.

Operating Systems

disk_requests = [95, 180, 34, 119, 11, 123, 62, 64]
# Set the initial disk head position
# Your code here

Need a hint?

Assign the number 50 directly to the variable head_position.

3

CORE LOGIC: Explain the LOOK algorithm order

Create a list called look_order that shows the order in which the disk head services requests using the LOOK algorithm starting from head_position. The head moves towards higher requests first, then reverses direction to service lower requests. Use the exact variable names disk_requests and head_position.

Operating Systems

disk_requests = [95, 180, 34, 119, 11, 123, 62, 64]
head_position = 50
# Create the LOOK algorithm order list
# Your code here

Need a hint?

First service requests greater than 50 in ascending order, then service requests less than 50 in descending order.

4

COMPLETION: Explain the C-LOOK algorithm order

Create a list called clook_order that shows the order in which the disk head services requests using the C-LOOK algorithm starting from head_position. The head moves towards higher requests first, then jumps back to the lowest request without servicing in reverse order. Use the exact variable names disk_requests and head_position.

Operating Systems

disk_requests = [95, 180, 34, 119, 11, 123, 62, 64]
head_position = 50
look_order = [62, 64, 95, 119, 123, 180, 34, 11]
# Create the C-LOOK algorithm order list
# Your code here

Need a hint?

Service requests greater than 50 in ascending order, then jump to the lowest requests and service them in ascending order.