Juniper JN0-214 Exam With Confidence Using Practice Dumps

KVM (Kernel-based Virtual Machine) is a popular open-source virtualization technology that allows you to run virtual machines (VMs) on Linux systems. Thevirshcommand-line tool is used to manage KVM VMs. Let’s analyze each option:

A. virt-install

Incorrect:Thevirt-installcommand is used to create and provision new virtual machines. It is not used to list running VMs.

B. virsh net-list

Incorrect:Thevirsh net-listcommand lists virtual networks configured in the KVM environment. It does not display information about running VMs.

C. virsh list

Correct:Thevirsh listcommand displays the status of virtual machines managed by the KVM hypervisor. By default, it shows only running VMs. You can use the--allflag to include stopped VMs in the output.

D. VBoxManage list runningvms

Incorrect:TheVBoxManagecommand is used with Oracle VirtualBox, not KVM. It is unrelated to KVM virtualization.

Why virsh list?

Purpose-Built for KVM: virshis the standard tool for managing KVM virtual machines, andvirsh listis specifically designed to show the status of running VMs.

Simplicity:The command is straightforward and provides the required information without additional complexity.

JNCIA Cloud References:

The JNCIA-Cloud certification emphasizes understanding virtualization technologies, including KVM. Managing virtual machines using tools likevirshis a fundamental skill for operating virtualized environments.

For example, Juniper Contrail supports integration with KVM hypervisors, enabling the deployment and management of virtualized network functions (VNFs). Proficiency with KVM tools ensures efficient management of virtualized infrastructure.

Docker is a popular containerization platform that relies on a container runtime to manage the lifecycle of containers. The container runtime is responsible for tasks such as creating, starting, stopping, and managing containers. Let’s analyze each option:

A. docker_cli

Incorrect: The Docker CLI (Command Line Interface) is a tool used to interact with the Docker daemon (dockerd). It is not a container runtime but rather a user interface for managing Docker containers.

B. containerd

Correct: containerd is the default container runtime used by Docker. It is a lightweight, industry-standard runtime that handles low-level container management tasks, such as image transfer, container execution, and lifecycle management. Docker delegates these tasks to containerd through the Docker daemon.

C. dockerd

Incorrect: dockerd is the Docker daemon, which manages Docker objects such as images, containers, networks, and volumes. While dockerd interacts with the container runtime, it is not the runtime itself.

D. cri-o

Incorrect: cri-o is an alternative container runtime designed specifically for Kubernetes. It implements the Kubernetes Container Runtime Interface (CRI) and is not used by Docker.

Why containerd?

Industry Standard: containerd is a widely adopted container runtime that adheres to the Open Container Initiative (OCI) standards.

Integration with Docker: Docker uses containerd as its default runtime, making it the correct answer in this context.

JNCIA Cloud References:

The JNCIA-Cloud certification emphasizes understanding containerization technologies and their components. Docker and its runtime (containerd) are foundational tools in modern cloud environments, enabling lightweight, portable, and scalable application deployment.

For example, Juniper Contrail integrates with container orchestration platforms like Kubernetes, which often use containerd as the underlying runtime. Understanding container runtimes is essential for managing containerized workloads in cloud environments.

Kubernetes combined with KubeVirt enables the hosting of virtual machines (VMs) alongside containerized workloads. This setup aligns with a specific cloud service model. Let’s analyze each option:

A. Software as a Service (SaaS)

Incorrect:SaaS delivers fully functional applications over the internet, such as Salesforce or Google Workspace. Hosting VMs using Kubernetes and KubeVirt does not fall under this category.

B. Platform as a Service (PaaS)

Incorrect:PaaS provides a platform for developers to build, deploy, and manage applications without worrying about the underlying infrastructure. While Kubernetes itself can be considered a PaaS component, hosting VMs goes beyond this model.

C. Infrastructure as a Service (IaaS)

Correct: IaaSprovides virtualized computing resources such as servers, storage, and networking over the internet. By hosting VMs using Kubernetes and KubeVirt, you are offering infrastructure-level services, which aligns with the IaaS model.

D. Bare Metal as a Service (BMaaS)

Incorrect:BMaaS provides direct access to physical servers without virtualization. Kubernetes and KubeVirt focus on virtualized environments, making this option incorrect.

Why IaaS?

Virtualized Resources:Hosting VMs using Kubernetes and KubeVirt provides virtualized infrastructure, which is the hallmark of IaaS.

Scalability and Flexibility:Users can provision and manage VMs on-demand, similar to traditional IaaS offerings like AWS EC2 or OpenStack.

JNCIA Cloud References:

The JNCIA-Cloud certification emphasizes understanding cloud service models, including IaaS. Recognizing how Kubernetes and KubeVirt fit into the IaaS paradigm is essential for designing hybrid cloud solutions.

For example, Juniper Contrail integrates with Kubernetes and KubeVirt to provide advanced networking and security features for IaaS-like environments.