305-300 Practice Test 14 — 15 Questions

Question 1

Which THREE features are provided by the Vagrant 'synced_folder' functionality?

Accepted Answer

Two-way synchronization. Synced folders provide shared storage, allow file editing on the host, and enable code synchronization between host and guest.

Answer

Automatic kernel updates

Answer

Remote SSH tunneling

Question 2

Which THREE directives are valid under the cloud-init 'users' configuration section?

Accepted Answer

name. 'name', 'ssh_authorized_keys', and 'groups' are all standard configuration keys for the user module.

Answer

expiration_date

Answer

security_level

Question 3

You are troubleshooting a container networking issue. You notice that traffic from the container is not being SNATed. What should you check in the iptables rules?

Accepted Answer

nat table, POSTROUTING chain. The POSTROUTING chain in the nat table is responsible for MASQUERADE rules used for SNAT.

Answer

nat table, PREROUTING chain

Answer

filter table, FORWARD chain

Answer

mangle table, OUTPUT chain

Question 4

Which file in a Vagrant project directory is processed by default to define the virtual environment configuration?

Accepted Answer

Vagrantfile. Vagrant looks for a file named 'Vagrantfile' in the directory where the 'vagrant' command is executed.

Answer

settings.json

Answer

provision.sh

Answer

config.yml

Question 5

You are configuring cloud-init to inject an SSH key into a new VM. Which directive in the configuration metadata ensures the key is added to the correct user's authorized_keys file?

Accepted Answer

ssh_authorized_keys. The 'ssh_authorized_keys' directive within the user object specifies which public keys should be injected into the ~/.ssh/authorized_keys file for that user.

Answer

users.ssh_key

Answer

ssh_keys

Answer

authorized_keys_file

Question 6

How do you define a new libvirt virtual network from an XML file named 'net.xml'?

Accepted Answer

virsh net-define net.xml. virsh net-define net.xml loads the network configuration into libvirt.

Answer

virsh net-load net.xml

Answer

virsh define net.xml

Answer

virsh net-create net.xml

Question 7

Which THREE of the following are common cloud-init modules?

Accepted Answer

packages. 'users-groups', 'runcmd', and 'packages' are all standard, well-documented modules in the cloud-init ecosystem.

Answer

network-bridge

Answer

disk-partition

Question 8

You are configuring LXC and want to set a CPU limit for a container. Which cgroup parameter is used to specify the quota of CPU time in microseconds?

Accepted Answer

lxc.cgroup.cpu.cfs_quota_us. lxc.cgroup.cpu.cfs_quota_us defines the number of microseconds the container can run in a period.

Answer

lxc.cgroup.cpu.limit

Answer

lxc.cgroup.cpu.shares

Answer

lxc.cgroup.cpu.period_us

Question 9

You are building a multi-stage Dockerfile and want to copy a binary from the 'builder' stage to the final stage. Which syntax is correct?

Accepted Answer

COPY --from=builder /bin/app /bin/app. 'COPY --from=stage_name source destination' is the syntax for multi-stage copying.

Answer

ADD --from=builder /bin/app /bin/app

Answer

COPY builder:/bin/app /bin/app

Answer

COPY --stage=builder /bin/app /bin/app

Question 10

Which TWO of the following are valid ways to manage storage pools using virsh?

Accepted Answer

virsh pool-create-as. The 'virsh pool-create-as' and 'virsh pool-define-as' commands are the standard ways to manage pools.

Answer

virsh pool-mount

Answer

virsh pool-resize

Answer

virsh pool-format

Question 11

You need to migrate a running QEMU VM to a remote host using live migration. Which command-line argument for QEMU-KVM initiates a migration to a target host at 192.168.1.50 on port 4444?

Accepted Answer

-migrate tcp:192.168.1.50:4444. The -migrate command or the migrate QMP command is used, but for the CLI argument, the migration URI must be defined.

Answer

-remote 192.168.1.50:4444

Answer

-live-migrate 192.168.1.50:4444

Answer

-incoming tcp:192.168.1.50:4444

Question 12

Which THREE configuration items can be managed via cloud-init 'write_files' module?

Accepted Answer

Target path (path). The 'write_files' module allows defining content, file permissions, and target paths for arbitrary files.

Answer

Service status

Answer

Kernel parameters

Question 13

A Docker container is failing to connect to an external database despite the host being able to ping it. You suspect a bridge networking issue. Which command allows you to inspect the current NAT rules created by Docker?

Accepted Answer

iptables -t nat -L -n. Docker manages iptables rules for container networking.

Answer

docker network inspect bridge

Answer

ip link show docker0

Answer

sysctl -a | grep net.bridge

Question 14

You are using Packer to automate a build. You notice the build fails because the 'communicator' cannot connect. Which type of communicator is most suitable for a KVM-based build where SSH is not yet configured?

Accepted Answer

none. The 'none' communicator is used when the builder handles the image creation without needing remote access, or 'ssh' if the guest OS supports it. However, if the build relies on console output/keystrokes, the 'none' communicator is often used alongside the boot command.

Answer

ssh

Answer

http

Answer

winrm

Question 15

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 specific binary for ARM system emulation.

Answer

qemu-x86_64-arm

Answer

qemu-arm

Answer

qemu-system-x86_64