CompTIA CompTIA Certifications XK0-005 Questions & Answers

• Question 161:

  A Linux administrator needs to expand a volume group using a new disk. Which of the following options presents the correct sequence of commands to accomplish the task?

  A. partprobe vgcreate lvextend

  B. lvcreate fdisk partprobe

  C. fdisk partprobe mkfs

  D. fdisk pvcreate vgextend

  Correct Answer: D

  Explanation: The correct sequence of commands to expand a volume group using a new disk is fdisk, pvcreate, vgextend. The fdisk command can be used to create a partition on the new disk with the type 8e (Linux LVM). The pvcreate command can be used to initialize the partition as a physical volume for LVM. The vgextend command can be used to add the physical volume to an existing volume group. The partprobe command can be used to inform the kernel about partition table changes, but it is not necessary in this case. The vgcreate command can be used to create a new volume group, not expand an existing one. The lvextend command can be used to extend a logical volume, not a volume group. The lvcreate command can be used to create a new logical volume, not expand a volume group. The mkfs command can be used to create a filesystem on a partition or a logical volume, not expand a volume group. References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 14: Managing Disk Storage, pages 462-463.

• Question 162:

  Which of the following technologies provides load balancing, encryption, and observability in containerized environments?

  A. Virtual private network

  B. Sidecar pod

  C. Overlay network

  D. Service mesh

  Correct Answer: D

  Explanation: "A service mesh controls the delivery of service requests in an application. Common features provided by a service mesh include service discovery, load balancing, encryption and failure recovery." The technology that provides load balancing, encryption, and observability in containerized environments is service mesh. A service mesh is a dedicated infrastructure layer that manages the communication and security between microservices in a distributed system. A service mesh consists of two components: a data plane and a control plane. The data plane is composed of proxies that are deployed alongside the microservices as sidecar pods. The proxies handle the network traffic between the microservices and provide features such as load balancing, encryption, authentication, authorization, routing, and observability. The control plane is responsible for configuring and managing the data plane and providing a unified interface for the administrators and developers. A service mesh can help improve the performance, reliability, and security of containerized applications and simplify the development and deployment process. A service mesh is the technology that provides load balancing, encryption, and observability in containerized environments. This is the correct answer to the question. The other options are incorrect because they either do not provide all the features of a service mesh (virtual private network or overlay network) or are not a technology but a component of a service mesh (sidecar pod). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 19: Managing Cloud and Virtualization Technologies, page 574. https://www.techtarget.com/searchitoperations/definition/service-mesh

• Question 163:

  Developers have requested implementation of a persistent, static route on the application server. Packets sent over the interface eth0 to 10.0.213.5/32 should be routed via 10.0.5.1. Which of the following commands should the administrator run to achieve this goal?

  A. route -i etho -p add 10.0.213.5 10.0.5.1

  B. route modify eth0 +ipv4.routes "10.0.213.5/32 10.0.5.1"

  C. echo "10.0.213.5 10.0.5.1 eth0" > /proc/net/route

  D. ip route add 10.0.213.5/32 via 10.0.5.1 dev eth0

  Correct Answer: D

  Explanation: The command ip route add 10.0.213.5/32 via 10.0.5.1 dev eth0 adds a static route to the routing table that sends packets destined for 10.0.213.5/32 (a single host) through the gateway 10.0.5.1 on the interface eth0. This is the correct way to achieve the goal. The other options are incorrect because they either use the wrong syntax (route -i etho -p add), the wrong command (route modify), or the wrong file (/proc/net/route). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 12: Managing Network Connections, page 379.

• Question 164:

  A systems administrator is tasked with creating a cloud-based server with a public IP address.

  

  Which of the following technologies did the systems administrator use to complete this task?

  A. Puppet

  B. Git

  C. Ansible

  D. Terraform

  Correct Answer: D

  Explanation: The systems administrator used Terraform to create a cloud-based server with a public IP address. Terraform is a tool for building, changing, and versioning infrastructure as code. Terraform can create and manage resources on different cloud platforms, such as AWS, Azure, or Google Cloud. Terraform uses a declarative syntax to describe the desired state of the infrastructure and applies the changes accordingly. Terraform can also assign a public IP address to a cloud server by using the appropriate resource attributes. This is the correct technology that the systems administrator used to complete the task. The other options are incorrect because they are either not designed for creating cloud servers (Puppet or Git) or not capable of assigning public IP addresses (Ansible). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 19: Managing Cloud and Virtualization Technologies, page 559.

• Question 165:

  A systems administrator is implementing a new service task with systems at startup and needs to execute a script entitled test.sh with the following content:

  

  The administrator tries to run the script after making it executable with chmod +x; however, the script will not run. Which of the following should the administrator do to address this issue? (Choose two.)

  A. Add #!/bin/bash to the bottom of the script.

  B. Create a unit file for the new service in /etc/systemd/system/ with the name helpme.service in the location.

  C. Add #!//bin/bash to the top of the script.

  D. Restart the computer to enable the new service.

  E. Create a unit file for the new service in /etc/init.d with the name helpme.service in the location.

  F. Shut down the computer to enable the new service.

  Correct Answer: BC

  Explanation: The administrator should do the following two things to address the issue: Add #!/bin/bash to the top of the script. This is called a shebang line and it tells the system which interpreter to use to execute the script. Without this line, the script will not run properly. The shebang line should be the first line of the script and should start with #! followed by the path to the interpreter. In this case, the interpreter is bash and the path is /bin/bash. The other option (A) is incorrect because the shebang line should be at the top, not the bottom of the script. Create a unit file for the new service in /etc/systemd/system/ with the name helpme.service in the location. This is necessary to register the script as a systemd service and enable it to run at startup. A unit file is a configuration file that defines the properties and behavior of a service, such as the description, dependencies, start and stop commands, and environment variables. The unit file should have the extension .service and should be placed in the /etc/systemd/system/ directory. The other option (E) is incorrect because /etc/init.d is the directory for init scripts, not systemd services. References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 14: Managing Processes and Scheduling Tasks, pages 429-430.

• Question 166:

  A Linux administrator has defined a systemd script docker-repository.mount to mount a volume for use by the Docker service. The administrator wants to ensure that Docker service does not start until the volume is mounted. Which of the following configurations needs to be added to the Docker service definition to best accomplish this task?

  A. After=docker-respository.mount

  B. ExecStart=/usr/bin/mount -a

  C. Requires=docker-repository.mount

  D. RequiresMountsFor=docker-repository.mount

  Correct Answer: C

  This option declares an explicit dependency between the Docker service and the docker- repository.mount unit. It means that the Docker service will not start unless the docker- repository.mount unit is successfully activated. This ensures that the volume is mounted before the Docker service tries to use it12.

  References: 1: systemd.unit - systemd unit configuration 2: How to mount host volumes into docker containers in Dockerfile during build

• Question 167:

  An administrator would like to mirror the website files on the primary web server, www1, to the backup web server, www2. Which of the following commands should the administrator use to most efficiently accomplish this task?

  A. [wwwl ] rsync --a --e ssh /var/www/html/ user1@www2 : /var/www/html

  B. [ wwwl ] scp --r /var/www/html user1@www2 : / var/www/html

  C. [www2 ] cd /var/www/html; wget --m http: //wwwl/

  D. [wwwl ] cd /var/www/html andand tar cvf -

  Correct Answer: A

  To mirror the website files on the primary web server, www1, to the backup web server, www2, the administrator can use the command rsync -a -e ssh /var/www/html/ user1@www2:/var/www/html (A). This will synchronize all files and directories under /var/www/html/ on www1 to /var/www/html on www2 using ssh as the remote shell. The -a option will preserve all attributes and permissions of the files. The other commands will not mirror the website files, but either copy them once, download them from a web server, or archive them. References: [CompTIA Linux+ Study Guide], Chapter 12: Troubleshooting Linux Systems, Section: Synchronizing Files with rsync [How to Use rsync Command in Linux]

• Question 168:

  After listing the properties of a system account, a systems administrator wants to remove the expiration date of a user account. Which of the following commands will accomplish this task?

  A. chgrp system accountname

  B. passwd -s accountname

  C. chmod -G system account name

  D. chage -E -1 accountname

  Correct Answer: D

  Explanation: The command chage -E -1 accountname will accomplish the task of removing the expiration date of a user account. The chage command is a tool for changing user password aging information on Linux systems. The -E option sets the expiration date of the user account, and the -1 value means that the account will never expire. The command chage -E -1 accountname will remove the expiration date of the user account named accountname. This is the correct command to use to accomplish the task. The other options are incorrect because they either do not affect the expiration date (chgrp, passwd, or chmod) or do not exist (chmod -G). References: CompTIA Linux+ (XK0- 005) Certification Study Guide, Chapter 15: Managing Users and Groups, page 467.

• Question 169:

  An administrator started a long-running process in the foreground that needs to continue without interruption. Which of the following keystrokes should the administrator use to continue running the process in the background?

  A. bg

  B. bg

  C. jobs -1

  D. bg and

  Correct Answer: A

  A long-running process is a program that takes a long time to complete or runs indefinitely on a Linux system. A foreground process is a process that runs in the current terminal and receives input from the keyboard and output to the screen.

  A background process is a process that runs in the background and does not interact with the terminal. A background process can continue running even if the terminal is closed or disconnected. To start a long-running process in the

  background, the user can append an ampersand (and) to the command, such as someapp and. This will run someapp in the background and return control to the terminal immediately.

  To move a long-running process from the foreground to the background, the user can use two keystrokes: Ctrl+Z and bg. The Ctrl+Z keystroke will suspend (pause) the foreground process and return control to the terminal. The bg keystroke

  will resume (continue) the suspended process in the background and detach it from the terminal. The statement B is correct.

  The statements A, C, and D are incorrect because they do not perform the desired task. The bg keystroke alone will not work unless there is a suspended process to resume. The Ctrl+B keystroke will not suspend the foreground process, but

  rather move one character backward in some applications. The jobs keystroke will list all processes associated with the current terminal. The bg and keystroke will cause an error because bg does not take any arguments. References: [How to

  Run Linux Processes in Background]

• Question 170:

  Which of the following specifications is used to perform disk encryption in a Linux system?

  A. LUKS

  B. TLS

  C. SSL

  D. NFS

  Correct Answer: A

  LUKS stands for Linux Unified Key Setup, which is a specification for disk encryption on Linux systems. LUKS allows users to encrypt partitions or entire disks using a passphrase or a key file. LUKS also supports multiple keys and key slots, which can be used to unlock the encrypted data. LUKS is compatible with various tools and utilities, such as cryptsetup, dm-crypt, and LVM. References: [How to Encrypt Partitions with LUKS on Linux]