Understanding Virtualization and Cloud Computing Concepts

Posted on Dec 13, 2025 in Computers

a) What are the disadvantages of virtualization?

b) What is the difference between distributed objects and RPC?
c) Define federated clouds.

a) Disadvantages of Virtualization

(Any 3 points for 2 marks)

1. Performance Overhead:
   Virtual machines run on top of a hypervisor, so applications may not perform as fast as on physical hardware.

2. High Initial Cost:
   Powerful servers, hypervisors, and storage systems are required, which increases setup cost.

3. Complex Management:
   Managing multiple VMs, snapshots, networks, and storage requires skilled administrators and increases complexity.

4. Security Risks:
   If the hypervisor is attacked, all VMs running on it are at risk.

5. Resource Contention:
   Multiple VMs share the same hardware, so one heavy VM can slow down others.

b) Difference Between Distributed Objects and RPC

(Write any 3 differences — 2 marks)

c) Define Federated Clouds

(2 marks)

Federated Cloud is a cloud computing model in which multiple cloud providers interconnect and work together, allowing users to access resources from different clouds as if they were a single unified cloud system.

Key points to include:

1. Combines public, private, or community clouds from different providers.

2. Provides resource sharing, load balancing, and interoperability between clouds.

3. Helps organizations avoid vendor lock-in and improves scalability.

a) Define virtualization. How does virtualization support cloud computing?
b) Explain different types of virtualization with suitable examples.

a) Define Virtualization. How does Virtualization Support Cloud Computing?

(3–4 marks)

Definition of Virtualization

Virtualization is a technology that allows a single physical hardware system to run multiple virtual machines (VMs), each acting like an independent computer. It separates the hardware layer from the software layer, using a hypervisor.

How Virtualization Supports Cloud Computing

1. Efficient Resource Utilization:
   Multiple VMs share the same hardware, reducing wastage and improving performance.

2. Scalability:
   Cloud providers can quickly create, modify, or delete virtual machines based on user demand.

3. Isolation:
   Each VM runs independently, so applications run securely without interfering with each other.

4. Cost Reduction:
   Hardware is used more efficiently, reducing costs for cloud providers and users.

5. Flexibility and Portability:
   Virtual machines can be easily moved between servers, enabling load balancing and disaster recovery.

6. Rapid Deployment:
   Cloud services (IaaS, PaaS) can instantly provision new VM instances using virtualization.

b) Explain Different Types of Virtualization with Suitable Examples.

(4–5 marks)

1. Hardware Virtualization

• Hypervisor controls hardware and creates multiple virtual machines.

• Example: VMware ESXi, Microsoft Hyper-V.

2. Operating System (OS) Virtualization

• Also called containerization.

• Multiple isolated user spaces run on a single OS kernel.

• Lightweight and fast.

• Example: Docker, LXC, Kubernetes pods.

3. Server Virtualization

• A physical server is divided into several virtual servers, each running its own OS.

• Used in data centers.

• Example: Creating multiple Linux/Windows server VMs on VMware/Hyper-V.

4. Storage Virtualization

• Combines multiple physical storage devices into one virtual storage pool.

• Improves performance and backup.

• Example: SAN (Storage Area Network), RAID, NetApp.

5. Network Virtualization

• Combines network resources into a single, software-managed virtual network.

• Helps in load balancing and traffic control.

• Example: VLANs, Software Defined Networking (SDN), VMware NSX.

6. Application Virtualization

• Applications run in a separate virtual environment without installing on the host OS.

• Example: Citrix Virtual Apps, Microsoft App-V.

7. Desktop Virtualization

• User desktops run on a central server instead of local machines.

• Accessed through thin clients.

• Example: Virtual Desktop Infrastructure (VDI), VMware Horizon.

a) What is MapReduce? Explain its architecture and working with an example.

b) Differentiate between HDFS and GFS.

a) What is MapReduce? Explain its architecture and working with an example.

(4–5 marks answer)

What is MapReduce?

MapReduce is a distributed data processing model used to handle very large datasets by dividing the work into two phases:

1. Map phase – processes input data and converts it into key–value pairs

2. Reduce phase – collects and combines these values to produce the final output

It is widely used in Hadoop to perform parallel processing across multiple nodes.

Architecture of MapReduce

1. Client (Job Submission)

   • User submits a MapReduce job.

2. Job Tracker / Resource Manager

   • Central master node.

   • Assigns tasks to worker nodes.

   • Tracks progress and handles failures.

3. Task Trackers / Node Managers

   • Worker nodes.

   • Execute map and reduce tasks assigned by the Job Tracker.

4. HDFS (Storage Layer)

   • Stores input data and final output.

   • Splits large data files into blocks that are processed in parallel.

Working of MapReduce (Step-by-Step)

1. Input Splitting

The large input file is divided into smaller parts (blocks). Each part is processed by a separate mapper.

2. Map Phase

Each mapper reads its portion of data and converts it into intermediate key-value pairs.
Example: A word in text may be converted into a key, and its occurrence is the value.

3. Shuffle and Sort Phase

The framework automatically collects all values belonging to the same key from different mappers.
Sorting ensures that keys reach reducers in an organized way.

4. Reduce Phase

Reducers take grouped values for each key and combine/summarize them to produce the final output.

5. Output Phase

The final processed result is stored back into HDFS.

Example (WITHOUT any code)

Consider a simple task such as counting how many times each word appears in a document.

• Map Phase:
  Each line of text is broken into words, and each word is given a count of 1.

• Shuffle & Sort:
  All occurrences of the same word are collected together.

• Reduce Phase:
  The counts for each word are added to get the total frequency.

This gives the final word count.

b) Differentiate Between HDFS and GFS

(3 marks answer)

a) Describe the fundamental features of the economic and business model behind cloud computing.
b) Which are the basic components of an IaaS-based solution for cloud computing?

Below is a clean, exam-ready 6–8 marks answer for both questions. Perfect for semester exams.

a) Describe the Fundamental Features of the Economic and Business Model Behind Cloud Computing.

(4 marks)

Cloud computing is built on a unique economic and business model that makes IT services affordable, scalable, and efficient. The fundamental features are:

1. Pay-as-You-Go Model (Utility-Based Pricing)

Users pay only for the resources they consume—such as compute hours, storage, or bandwidth.
No upfront investment is needed.

2. Elasticity and Scalability

Resources automatically scale up or down depending on demand.
This reduces costs during low usage and supports high demand when needed.

3. Reduced Capital Expenditure (CapEx)

Organizations do not need to buy physical servers, storage, or networking equipment.
Cloud shifts spending to Operational Expenditure (OpEx).

4. Multi-Tenancy

Several customers share the same cloud infrastructure securely.
This reduces costs for both provider and users.

5. Economies of Scale

Cloud providers purchase hardware in bulk and run massive data centers, reducing costs per unit of computing.

6. Self-Service and On-Demand Availability

Users can instantly provision new servers, storage, or applications without waiting for IT staff.
Faster time to market → more business agility.

7. Service-Based Approach

Cloud offers services at different levels—IaaS, PaaS, SaaS—allowing businesses to select what they need and avoid unnecessary spending.

b) Which Are the Basic Components of an IaaS-Based Solution for Cloud Computing?

(3–4 marks)

IaaS (Infrastructure as a Service) provides virtualized infrastructure over the internet. The basic components are:

1. Compute Resources (Virtual Machines / CPU / RAM)

Provide processing power through virtual machines or containers.
Users can choose CPU cores, memory size, and machine type.

2. Storage Resources

Includes block storage, object storage, and file storage.
Used to store data, backups, logs, and application files.

3. Networking Resources

Virtual networks, load balancers, firewalls, IP addresses, VPN, and routing.
Enable communication between VMs and external networks.

4. Virtualization Layer (Hypervisor)

Manages virtual machines and isolates them from each other.
Examples: VMware, KVM, Xen.

5. Management and Monitoring Tools

Dashboards, APIs, billing tools, and automation services.
Help users deploy, monitor, and control infrastructure easily.

6. Security Services

Identity management, encryption, access control, firewalls, and threat detection.

a) What is service-oriented computing and market-oriented cloud computing?

b) Discuss RPC and how it enables inter-process communication.

Here is a short, crisp, exam-ready answer (6 marks total).
Perfect for writing in limited time.

a) What is Service-Oriented Computing and Market-Oriented Cloud Computing?

(3 marks)

Service-Oriented Computing (SOC)

Service-oriented computing is a model in which applications are designed as independent, reusable services that communicate using standard protocols.
It follows SOA principles like loose coupling, interoperability, and reusability.
Example: Payment service, authentication service, weather service.

Market-Oriented Cloud Computing

Market-oriented cloud computing treats cloud resources as commodities that can be traded based on supply and demand.
It uses models like pay-as-you-use, dynamic pricing, and SLAs to allocate resources efficiently.
Example: Amazon EC2 spot instances, where users bid for resources.

b) Discuss RPC and How It Enables Inter-Process Communication.

(3 marks)

RPC (Remote Procedure Call)

RPC is a mechanism that allows a program to call a function on another machine as if it were a local call. It hides low-level networking details from the programmer.

How RPC Enables Inter-Process Communication

• Works on a client–server model where the client requests a function and the server executes it.

• Uses stubs to convert data into messages (marshalling) and send them across the network.

• Provides transparent communication, meaning the user just calls a function without worrying about sockets or protocols.

• The server processes the request and returns the result, enabling smooth communication between distributed processes.

Write a short note on the following:

(i) Enterprise Software.
(ii) Cloud Security Mechanisms.

(i) Enterprise Software

Enterprise software refers to large-scale applications designed to support the core operations of an organization. These systems help businesses manage processes like finance, HR, supply chain, customer relationships, and data management.

Key points:

• Used by big organizations to improve productivity and coordination.

• Supports business-wide integration and automates processes.

• Examples: ERP (Enterprise Resource Planning), CRM (Customer Relationship Management), SCM (Supply Chain Management), HRMS, and CRM tools.

• Ensures scalability, reliability, and security for enterprise operations.

(ii) Cloud Security Mechanisms

Cloud security mechanisms are the techniques and tools used to protect cloud data, applications, and infrastructure from threats.

Main mechanisms include:

1. Identity and Access Management (IAM):
   Controls who can access cloud resources.

2. Authentication & Authorization:
   Ensures only verified users can perform allowed operations.

3. Encryption:
   Protects data at rest and in transit.

4. Firewalls & Network Security:
   Prevent unauthorized network access.

5. Intrusion Detection and Prevention Systems (IDS/IPS):
   Detects and blocks suspicious activity.

6. Security Monitoring & Auditing:
   Tracks usage, logs events, and ensures compliance.

These mechanisms help ensure confidentiality, integrity, and availability of cloud services.