Os 2

Question 1

What is cloud computing and why do we use it?

Answer 1

On‑demand delivery of IT resources (servers, storage, databases, applications) over the Internet, billed pay‑as‑you‑go. We use it to avoid large upfront costs, scale instantly with demand, and gain global access with built‑in reliability.

Question 2

What is cloud elasticity in the context of cloud computing?

Answer 2

The ability of a cloud platform to automatically scale resources up or down (compute, storage, network) in response to workload changes, so you only pay for what you need when you need it.

Question 3

What is the difference between SaaS, PaaS, and IaaS?

Answer 3

IaaS (Infrastructure as a Service): You rent virtual hardware (VMs, storage, networks). You manage OS and apps.                  
• PaaS (Platform as a Service): You deploy code on a managed runtime (databases, web servers). The provider manages OS and middleware.
• SaaS (Software as a Service): You use complete applications via browser or API. The provider manages everything underneath.

Question 4

What is a file system?

Answer 4

The method and data structures an OS uses to organize, store, retrieve, and manage files on a storage device (e.g., FAT32, NTFS, ext4).

Question 5

What is Direct Memory Access (DMA)?

Answer 5

A hardware feature allowing peripherals to transfer data directly to/from main memory without continuous CPU intervention, freeing the CPU for other tasks and improving throughput.

Question 6

What is virtualization and why do we need it?

Answer 6

Abstraction of physical hardware into multiple isolated virtual machines or containers. We need it to improve hardware utilization, enable flexible deployment, support live migration, and provide strong isolation between workloads.

Question 7

What is the purpose of containers in cloud computing (e.g., Docker)?

Answer 7

To package applications and dependencies into lightweight, portable units that share the host OS kernel, enabling fast startup, consistent behavior across environments, efficient resource use, and easy scaling and orchestration.

Question 8

What is a deadlock?

Answer 8

A situation where two or more processes each wait indefinitely for resources held by the others, so none can proceed.