305-300 Practice Test 4 — 25 Questions

Question 1

You want to limit the bandwidth of a virtual network interface. Which XML element within <interface> allows you to configure this?

Accepted Answer

. The element allows setting inbound and outbound throughput limits.

Answer

<limit-rate>1000</limit-rate>

Answer

<network-speed>1000</network-speed>

Answer

<traffic-control>1000</traffic-control>

Question 2

Which command is used to start a VM that has been defined?

Accepted Answer

virsh start vm_name. virsh start vm_name boots the virtual machine.

Answer

virsh launch vm_name

Answer

virsh boot vm_name

Answer

virsh run vm_name

Question 3

When cleaning up Docker resources, which command will remove all stopped containers, unused networks, and dangling images in one step?

Accepted Answer

docker system prune. docker system prune removes all unused data, which is the most efficient cleanup method.

Answer

docker container prune

Answer

docker volume prune

Answer

docker image prune -a

Answer

docker cleanup

Question 4

Which TWO types of namespaces are commonly used to achieve container isolation in Linux?

Accepted Answer

Network. Network and PID namespaces are fundamental for containerization.

Answer

GPU

Answer

CPU

Answer

Kernel

Question 5

Which TWO of the following are valid ways to trigger provisioning in Vagrant?

Accepted Answer

vagrant provision. 'vagrant up --provision' runs provisioners during startup, and 'vagrant provision' runs them on a running machine.

Answer

vagrant start

Answer

vagrant reload --provision

Answer

vagrant apply

Question 6

How can you force a refresh of a libvirt storage pool named 'isos'?

Accepted Answer

virsh pool-refresh isos. virsh pool-refresh isos triggers a re-scan of the storage pool.

Answer

virsh refresh-pool isos

Answer

virsh pool-update isos

Answer

virsh pool-reload isos

Question 7

Which TWO of the following are benefits of using the QCOW2 image format?

Accepted Answer

Dynamic allocation (sparse files). Snapshots and dynamic allocation are key benefits of QCOW2.

Answer

Multi-host file locking

Answer

Hardware acceleration

Answer

Native encryption for all filesystems

Question 8

Which TWO of the following commands are used for VM disk image management?

Accepted Answer

qemu-img create. qemu-img info and qemu-img create are standard image management commands.

Answer

qemu-img list

Answer

qemu-img status

Answer

qemu-img format

Question 9

You are debugging a Docker network issue where containers on different hosts cannot communicate. Which network driver is specifically designed to support multi-host overlay networking?

Accepted Answer

overlay. The 'overlay' driver in Docker creates a distributed network among multiple Docker daemon hosts.

Answer

bridge

Answer

macvlan

Answer

ipvlan

Answer

host

Question 10

In the context of virtualization, what does 'ballooning' refer to?

Accepted Answer

Dynamically resizing guest memory. Memory ballooning allows the hypervisor to reclaim unused RAM from a guest VM and reallocate it to other VMs.

Answer

Scaling network bandwidth for a VM

Answer

Increasing the number of virtual CPUs

Answer

Compressing disk images on the fly

Question 11

Which QEMU-KVM feature allows you to save the state of a VM to a file and resume it later?

Accepted Answer

virsh save. The 'virsh save' command creates a state file, which can be restored with 'virsh restore'.

Answer

virsh snapshot

Answer

virsh checkpoint

Answer

virsh suspend

Question 12

What does 'QEMU' stand for?

Accepted Answer

Quick Emulator. Quick Emulator.

Answer

Quantum Emulator

Answer

Quick Execution Machine Utility

Answer

Quality Emulator

Question 13

Which THREE of the following XML elements are used to define a virtual disk in a domain?

Accepted Answer

. , , and are the primary sub-elements of a entry.

Answer

<mount-point path='/'>

Answer

Question 14

When configuring a systemd-nspawn container, what is the effect of the --private-network option?

Accepted Answer

It isolates the container's network from the host. The --private-network flag creates a virtual network namespace for the container, ensuring it cannot access the host's network interfaces.

Answer

It forces the container to use a bridge

Answer

It disables network encryption

Answer

It restricts access to localhost

Answer

It prevents the container from starting

Question 15

Which THREE of the following are components of the Docker architecture?

Accepted Answer

Docker Daemon. Docker client, daemon, and registry are the three core components.

Answer

Docker Kernel

Answer

Docker GUI

Question 16

Which THREE of the following are valid Libvirt storage pool types?

Accepted Answer

iscsi. Libvirt supports various backends for storage including directories, LVM volume groups, and iSCSI targets.

Answer

ram

Answer

usb

Question 17

You need to convert a raw disk image to QCOW2 format to enable snapshotting. Which command is correct?

Accepted Answer

qemu-img convert -f raw -O qcow2 source.img target.qcow2. qemu-img convert -f raw -O qcow2 source.img target.qcow2 is the standard syntax.

Answer

qemu-img convert -i raw -o qcow2 source.img target.qcow2

Answer

virsh image-convert source.img target.qcow2

Answer

qemu-img change -f raw -t qcow2 source.img

Question 18

You have an active domain named 'myvm'. How do you gracefully shut it down?

Accepted Answer

virsh shutdown myvm. virsh shutdown myvm sends an ACPI signal to the guest for a graceful shutdown.

Answer

virsh stop myvm

Answer

virsh poweroff myvm

Answer

virsh destroy myvm

Question 19

Which THREE of the following are valid components of a libvirt domain XML configuration?

Accepted Answer

. , , and are standard top-level or child blocks in the domain XML.

Answer

<kernel-module>

Answer

<network-config>

Question 20

You are using Packer to build a custom image for KVM. Which HCL2 block is specifically required to define the virtualization parameters like memory and CPU for the builder?

Accepted Answer

qemuargs. The 'qemu' builder in Packer utilizes specific configuration blocks to define virtual hardware settings when interfacing with KVM/QEMU.

Answer

provisioners

Answer

post-processors

Answer

boot_command