305-300 Practice Test 4 — 10 Questions

Question 1

Which hypervisor is known for being 'Type 2'?

Accepted Answer

VirtualBox. VirtualBox is classified as a Type 2 hypervisor because it runs as an application on top of a host operating system (Windows, Linux, macOS), relying on the host OS for scheduling, memory management, and I/O. It does not run directly on bare metal like Type 1 hypervisors. This hosted architecture is the defining characteristic of Type 2.

Answer

KVM

Answer

ESXi

Answer

Xen

Question 2

Which flag is used to run a container in the background?

Accepted Answer

-d. The `-d` (or `--detach`) flag tells `docker run` to start the container and immediately return control to the shell, running the container in the background. Without it, the container runs in the foreground and attaches its STDOUT/STDERR to your terminal, blocking the prompt until the process exits. This is the standard way to launch long-running services like web servers or databases.

Answer

-t

Answer

-b

Answer

-i

Question 3

In cloud-init, which syntax is required at the very beginning of the configuration file to ensure it is recognized as a cloud-config script?

Accepted Answer

#cloud-config. Cloud-init identifies a cloud-config file by the literal header #cloud-config on the very first line. Without this exact shebang-style marker, cloud-init treats the payload as a different user-data format (e.g., shell script or MIME multipart) and will not process the YAML directives.

Answer

#!/bin/bash

Answer

#cloud-init

Answer

---

Question 4

Which command-line option is used to run a Docker container in the background (detached mode)?

Accepted Answer

-d. The -d (or --detach) flag runs a Docker container in the background, returning the container ID and freeing the terminal. This is the standard way to start long-running services like web servers without blocking the shell. Combined with -p for port mapping and --name for identification, it is the canonical detached-mode invocation.

Answer

-i

Answer

--bg

Answer

-b

Answer

-t

Question 5

Which TWO components are defined in a Packer 'build' block?

Accepted Answer

sources. In a Packer HCL2 template, the build block is where you declare the sources (option C) that Packer will use to create the image, referencing source blocks defined elsewhere in the template, and the provisioners (option E) that run during the build to customize the machine before the image is captured. Both sources and provisioners are valid arguments inside a build block, e.g. build { sources = ["source.amazon-ebs.example"] provisioners = [ ... ] }. Option A (builders) is not correct because in HCL2 templates the builder is defined inside a source block, not directly as a build block argument. Option B (plugins) is not a build block argument; plugins are installed via packer init and referenced through their source types. Option D (variables) is not defined inside the build block; variables are declared in variable blocks and referenced with var.<name>.

Answer

builders

Answer

plugins

Answer

variables

Question 6

Which tool is commonly used alongside Packer to validate the configuration file for syntax errors before attempting a build?

Accepted Answer

packer validate. `packer validate` is the built-in Packer subcommand that parses a template (HCL2 or JSON) and verifies its syntax, required fields, and referenced variables/builders before any build is attempted. It catches schema errors, missing required attributes, and invalid references without provisioning any infrastructure. This makes it the standard pre-build sanity check in CI pipelines alongside `packer fmt`.

Answer

packer fmt

Answer

packer lint

Answer

packer check

Question 7

Which utility is best for creating a new libvirt storage pool?

Accepted Answer

virsh pool-define-as. virsh pool-define-as creates a persistent storage pool definition in libvirt's configuration without starting it, which is the correct first step for creating a new pool. After defining, you run virsh pool-build (if needed) and virsh pool-start to activate it.

Answer

virsh pool-create

Answer

virt-pool-builder

Answer

virsh add-pool

Question 8

Which TWO of the following are valid storage drivers used by Docker to manage image layers?

Accepted Answer

overlay2. overlay2 (A) is a valid Docker storage driver that uses the OverlayFS union filesystem to stack image layers and is the default driver on most modern Linux distributions. aufs (E) is also a valid Docker storage driver, historically used on Ubuntu/Debian, that implements a union mount to manage image layers. ext4 (B) is a filesystem, not a Docker storage driver, so it cannot manage image layers. vfs-driver (C) is not a real driver name; the actual driver is 'vfs', and it is a simple non-union driver, but the option as written is incorrect. zfs-layer (D) is not a valid driver name; the actual Docker driver is 'zfs', so this option is incorrect.

Answer

ext4

Answer

vfs-driver

Answer

zfs-layer

Question 9

You are using QEMU to emulate an ARM architecture on an x86 host. Which binary would you typically use to execute this?

Accepted Answer

qemu-system-arm. qemu-system-arm is the QEMU binary that emulates a full ARM system, including CPU, memory, and peripherals, allowing you to run an ARM operating system on an x86 host. The 'system' prefix indicates full-system emulation, as opposed to user-mode emulation. This is the correct binary for booting an ARM kernel or OS image.

Answer

qemu-x86_64-arm

Answer

qemu-arm

Answer

qemu-system-x86_64

Question 10

Which command lists all Docker images currently on the host?

Accepted Answer

docker images. 'docker images' queries the local image store and lists all images present on the host, showing repository, tag, image ID, creation time, and size. It is the canonical command for inspecting locally cached images before running or removing them.

Answer

docker ps

Answer

docker show

Answer

docker list