Virtualization methods differ in how they utilize hardware resources. Let's analyze each option:
A . OS-level virtualization
Correct: OS-level virtualization (e.g., containers) uses the host operating system's kernel to run isolated user-space instances (containers). Since containers share the host OS kernel, there is less duplication of hardware resources compared to other virtualization methods.
B . hardware-assisted virtualization
Incorrect: Hardware-assisted virtualization (e.g., Intel VT-x, AMD-V) enables full virtual machines (VMs) to run on physical hardware. Each VM includes its own operating system, leading to duplication of resources like memory and CPU.
C . full virtualization
Incorrect: Full virtualization involves running a complete guest operating system on top of a hypervisor. Each VM requires its own OS, resulting in significant resource duplication.
D . paravirtualization
Incorrect: Paravirtualization modifies the guest operating system to communicate directly with the hypervisor. While it reduces some overhead compared to full virtualization, it still requires separate operating systems for each VM, leading to resource duplication.
Why OS-Level Virtualization?
Resource Efficiency: Containers share the host OS kernel, eliminating the need for multiple operating systems and reducing resource duplication.
Lightweight: Containers are faster to start and consume fewer resources compared to VMs.
JNCIA Cloud Reference:
The JNCIA-Cloud certification emphasizes understanding virtualization technologies, including OS-level virtualization. Containers are a key component of modern cloud-native architectures due to their efficiency and scalability.
For example, Juniper Contrail integrates with container orchestration platforms like Kubernetes to manage OS-level virtualization workloads efficiently.
Reference:
Docker Documentation: Container Basics
Juniper JNCIA-Cloud Study Guide: Virtualization