I/O Scheduling and Performance Optimization: Master I/O Management

Question 1

Which I/O scheduling algorithm operates on a first-come, first-served basis?

Accepted Answer

FCFS

Answer

SSTF

Answer

SCAN

Question 2

What is a primary benefit of utilizing the SCAN algorithm for I/O scheduling?

Accepted Answer

Minimizes seek time by optimizing disk arm movement

Answer

Enhances system throughput by prioritizing critical requests

Answer

Reduces disk fragmentation by balancing data distribution

Question 3

What is the overarching objective of I/O scheduling algorithms?

Accepted Answer

Optimizing system resources to enhance performance

Answer

Minimizing data latency to improve responsiveness

Answer

Ensuring data integrity to prevent data loss

Question 4

What is a potential limitation of the SSTF algorithm in I/O scheduling?

Accepted Answer

Can lead to request starvation due to continuous servicing of nearby requests

Answer

Increases seek time by focusing on geographically close requests

Answer

Causes data loss by overwriting existing data

Question 5

Which metric is primarily used to evaluate the efficiency of I/O scheduling algorithms?

Accepted Answer

Throughput: Number of I/O requests processed per unit time

Answer

Latency: Time taken to process I/O requests

Answer

Response time: Time elapsed from request initiation to completion

Question 6

Explain the fundamental difference between preemptive and non-preemptive I/O scheduling.

Accepted Answer

Preemptive scheduling allows ongoing requests to be interrupted for higher priority requests, while non-preemptive does not.

Answer

Non-preemptive scheduling allows ongoing requests to be interrupted for higher priority requests, while preemptive does not.

Answer

Both preemptive and non-preemptive scheduling allow ongoing requests to be interrupted.

Question 7

What is a key advantage of employing the SCAN algorithm for I/O scheduling?

Accepted Answer

Prioritizes requests based on their distance from the current disk arm position

Answer

Enhances system stability by preventing data corruption

Answer

Reduces memory usage by optimizing data storage

Question 8

What is the primary distinction between FCFS and SSTF I/O scheduling algorithms?

Accepted Answer

FCFS processes requests in the order they arrive, while SSTF processes requests based on their distance from the disk head

Answer

SSTF processes requests in the order they arrive, while FCFS processes requests based on their distance from the disk head

Answer

Both FCFS and SSTF process requests based on their arrival time.

Question 9

Which non-preemptive I/O scheduling algorithm assigns processes to the I/O device in the order they arrive, ensuring fairness?

Accepted Answer

FCFS (First-Come First-Served)

Answer

SSTF (Shortest Seek Time First)

Answer

SCAN (Scanning)

Answer

C-SCAN (Circular Scanning)

Question 10

Which I/O scheduling algorithm strives to reduce seek time by prioritizing I/O requests located closest to the current disk head position?

Accepted Answer

SSTF (Shortest Seek Time First)

Answer

FCFS (First-Come First-Served)

Answer

SCAN (Scanning)

Answer

C-SCAN (Circular Scanning)

Question 11

Which I/O scheduling algorithm is a specialized version of SCAN that restricts arm movement to a single direction, preventing unnecessary reversals?

Accepted Answer

C-SCAN (Circular Scanning)

Answer

FCFS (First-Come First-Served)

Answer

SSTF (Shortest Seek Time First)

Answer

SCAN (Scanning)

Question 12

When selecting the most suitable I/O scheduling algorithm for a specific system, which factor is typically NOT taken into consideration?

Accepted Answer

Financial cost of implementing the algorithm

Answer

I/O device type and characteristics

Answer

Arrival rate and pattern of I/O requests

Answer

Operating system running on the system

Question 13

Which advantage is commonly associated with the FCFS I/O scheduling algorithm?

Accepted Answer

Simplicity of implementation and fairness

Answer

Minimization of seek time

Answer

Prioritization of large I/O requests

Answer

Enhancement of system throughput

Question 14

Which disadvantage is inherent to the SSTF I/O scheduling algorithm?

Accepted Answer

Potential starvation of processes with large I/O requests

Answer

Complexity in implementation

Answer

Unfair treatment of processes with small I/O requests

Answer

Inability to minimize seek time

Question 15

When evaluating I/O scheduling algorithms, why are average seek time and throughput important considerations?

Accepted Answer

They indicate algorithm efficiency and overall system performance.

Answer

Only disk scheduling algorithms require these metrics for analysis.

Answer

These metrics are crucial for determining the system's theoretical maximum performance.

Answer

The question lacks sufficient information to answer this question.

Question 16

How does a sequential disk access pattern affect the performance of the SCAN algorithm compared to a random disk access pattern?

Accepted Answer

Sequential access improves SCAN performance by reducing head movement.

Answer

Sequential access worsens SCAN performance by increasing head movement.

Answer

Random access improves SCAN performance by distributing head movement.

Answer

Random access worsens SCAN performance by concentrating head movement.

Question 17

Which scheduling algorithm strictly adheres to the queue discipline, servicing requests in the order they are received?

Accepted Answer

First-Come First-Served (FCFS)

Answer

Shortest Seek Time First (SSTF)

Answer

Scan Algorithm (SCAN)

Question 18

Which algorithm optimizes disk arm movement to minimize seek time by prioritizing requests closest to the current arm position?

Accepted Answer

SSTF

Answer

FCFS

Answer

SCAN

Question 19

Which of the following is not a crucial factor when choosing an appropriate scheduling algorithm for a system?

Accepted Answer

Total memory size

Answer

Characteristics of I/O requests

Answer

Disk hardware capabilities

Question 20

What is the primary advantage of using the FCFS algorithm?

Accepted Answer

Simplicity, fairness, and ease of implementation

Answer

Reduced risk of starvation

Answer

Increased disk throughput

Question 21

What is a potential limitation of the SCAN algorithm?

Accepted Answer

Increased seek time for requests near the outer edges of the disk

Answer

Possibility of starvation for requests in certain disk regions

Answer

High implementation complexity

Question 22

Which scheduling algorithm mimics the behavior of an elevator servicing multiple floors in a building?

Accepted Answer

SCAN

Answer

FCFS

Answer

SSTF

Question 23

Which factor is irrelevant when choosing an I/O scheduling algorithm?

Accepted Answer

CPU speed

Answer

I/O request arrival rate

Answer

Disk speed

Question 24

What is the main objective of employing I/O scheduling algorithms?

Accepted Answer

Minimize the average wait time for I/O requests

Answer

Maximize Central Processing Unit (CPU) utilization

Answer

Minimize the number of disk head movements

Question 25

Which I/O scheduling algorithm serves requests in the order they arrive, ensuring that the first request to arrive is processed first?

Accepted Answer

FCFS

Answer

SSTF

Answer

SCAN

Question 26

Which I/O scheduling algorithm prioritizes processes based on their arrival time, ensuring that the first process in the queue is served first?

Accepted Answer

FCFS (First-Come, First-Served)

Answer

SCAN (Elevator Algorithm)

Answer

SSTF (Shortest Seek Time First)

Answer

C-SCAN (Circular SCAN)

Question 27

What is a primary advantage of using the SSTF algorithm for I/O scheduling?

Accepted Answer

It minimizes the average seek time, improving performance.

Answer

It ensures fairness among processes.

Answer

It increases system throughput.

Answer

It prevents starvation.

Question 28

In which scenario should the SCAN algorithm be favored over the C-SCAN algorithm for I/O scheduling?

Accepted Answer

When the disk head needs to move in both directions to serve requests.

Answer

When the disk is heavily loaded.

Answer

When the disk head only needs to move in one direction.

Question 29

How does fragmentation affect the performance of an I/O scheduling algorithm?

Accepted Answer

It increases seek time, reducing overall performance.

Answer

It has no impact on performance.

Answer

It only affects disk-based systems.

Answer

It improves seek time, increasing performance.

Question 30

What is a key benefit of implementing a multi-level feedback queue in a system?

Accepted Answer

It enhances the performance of interactive applications.

Answer

It increases system throughput.

Answer

It eliminates starvation.

Answer

It reduces the overhead of context switching.

Question 31

What is the primary function of a load balancer in performance optimization?

Accepted Answer

It distributes incoming requests across multiple servers to balance the load and improve responsiveness.

Answer

It manages memory allocation.

Answer

It schedules processes and threads.

Question 32

What is the primary goal of performance tuning?

Accepted Answer

To optimize the efficiency and utilization of a system.

Answer

To reduce hardware costs.

Answer

To eliminate bugs and errors.

Answer

To enhance user satisfaction.

Question 33

What is a potential trade-off that may need to be considered during performance optimization?

Accepted Answer

Increased cost or complexity of implementation.

Answer

Improved security.

Answer

Reduced system reliability.

Question 34

Which of the following is NOT a commonly used performance metric for evaluating I/O scheduling algorithms?

Accepted Answer

Memory usage

Answer

Throughput

Answer

Response time

Answer

Average waiting time

Question 35

What is the ultimate objective of performance optimization in an operating system?

Accepted Answer

Maximize system throughput while minimizing response time.

Answer

Enhance user experience.

Answer

Reduce memory usage.

Question 36

What is the primary drawback of using a preemptive scheduling algorithm?

Accepted Answer

Increased overhead due to context switching

Answer

Increased memory consumption

Answer

Unpredictable response times

Answer

Reduced system stability

Question 37

A key benefit of employing a multi-level feedback queue scheduler is:

Accepted Answer

Improved fairness and response time for interactive processes.

Answer

Increased throughput for CPU-intensive processes.

Answer

Reduced overhead compared to round-robin scheduling.

Question 38

What is the main purpose of a thrashing algorithm in an operating system?

Accepted Answer

To detect and prevent excessive paging activity.

Answer

To handle hardware interruptions.

Answer

To allocate memory to processes in an efficient manner.

Answer

To schedule processes for optimal execution.

Question 39

Which of the following is a limitation of virtual memory systems?

Accepted Answer

Increased memory overhead and slower access times.

Answer

Security vulnerabilities due to shared memory.

Answer

Incompatibility with specific software applications.

Answer

Limited capacity relative to physical memory.

Question 40

What is the primary function of a Memory Management Unit (MMU)?

Accepted Answer

To translate virtual addresses into their corresponding physical addresses.

Answer

To dynamically allocate memory to processes.

Answer

To prevent memory leaks.

Question 41

Which I/O scheduling algorithm prioritizes requests on a first-come, first-served basis?

Accepted Answer

FCFS (First-Come, First-Served)

Answer

C-SCAN (Circular SCAN)

Answer

SCAN (Elevator Algorithm)

Answer

SSTF (Shortest Seek Time First)

Question 42

Which factor does not significantly influence the performance of an I/O scheduling algorithm?

Accepted Answer

CPU speed

Answer

Disk speed

Answer

Seek time

Answer

Number of I/O requests

Question 43

What is the primary goal of I/O scheduling?

Accepted Answer

Minimize average waiting time and turnaround time

Answer

Maximize CPU utilization

Answer

Reduce disk fragmentation

Answer

Increase memory allocation

Question 44

Which performance metric measures the time taken for an I/O request to be fulfilled?

Accepted Answer

Response time

Answer

Transfer time

Answer

Seek time

Answer

Latency

Question 45

What is a potential issue with using the SCAN algorithm?

Accepted Answer

It can cause starvation if the disk head repeatedly moves in one direction, neglecting requests on the opposite side of the disk.

Answer

It requires a large amount of memory.

Answer

It is too complex to implement.

Question 46

Which I/O scheduling algorithm prioritizes the disk request closest to the read/write head?

Accepted Answer

SSTF (Shortest Seek Time First)

Answer

FCFS (First Come, First Served)

Answer

C-SCAN

Answer

SCAN

Question 47

What is a benefit of using the SCAN algorithm for I/O scheduling?

Accepted Answer

Minimizes average seek time.

Answer

Prioritizes shorter I/O requests.

Answer

Guarantees fair access for all requests.

Answer

Improves cache hit rate.

Question 48

Which factor does NOT directly influence the choice of the best I/O scheduling algorithm?

Accepted Answer

Network topology

Answer

System load

Answer

Disk access patterns

Answer

Workload characteristics

Question 49

How can virtual memory help improve I/O performance when physical memory is limited?

Accepted Answer

By caching frequently accessed data in faster memory.

Answer

By compressing data before storing it in virtual memory.

Answer

By using a dedicated portion of virtual memory for I/O operations.

Answer

By increasing the size of the page file.

Question 50

Which Linux utility is specifically designed to monitor and analyze I/O performance?

Accepted Answer

iostat

Answer

netstat

Answer

top

Answer

ps

Question 51

How does file system fragmentation impact I/O performance?

Accepted Answer

It increases disk seek times, leading to slower data access.

Answer

It improves data security by spreading data across the disk.

Answer

It can cause data loss due to scattered data placement.

Answer

It reduces the amount of available disk space.

Question 52

Which technique is used to minimize file system fragmentation?

Accepted Answer

Disk defragmentation

Answer

Disk compression

Answer

Disk mirroring

Answer

Disk encryption

Question 53

How do solid-state drives (SSDs) impact I/O performance compared to traditional hard disk drives (HDDs)?

Accepted Answer

SSDs have significantly faster read/write speeds due to their lack of moving parts.

Answer

SSDs typically have larger storage capacities than HDDs.

Answer

SSDs are less reliable than HDDs.