CompTIA CompTIA Certifications XK0-005 Questions & Answers

• Question 241:

  Which of the following tools is BEST suited to orchestrate a large number of containers across many different servers?

  A. Kubernetes

  B. Ansible

  C. Podman

  D. Terraform

  Correct Answer: A

  Explanation: The tool that is best suited to orchestrate a large number of containers across many different servers is Kubernetes. Kubernetes is an open-source platform for managing containerized applications and services. Kubernetes allows the administrator to deploy, scale, and update containers across a cluster of servers, as well as to automate the configuration and coordination of the containers. Kubernetes also provides features such as service discovery, load balancing, storage management, security, monitoring, and logging. Kubernetes can handle complex and dynamic workloads and ensure high availability and performance of the containers. Kubernetes is the tool that is best suited to orchestrate a large number of containers across many different servers. This is the correct answer to the question. The other options are incorrect because they either do not orchestrate containers (Ansible or Terraform) or do not operate across many different servers (Podman). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 19: Managing Cloud and Virtualization Technologies, page 573.

• Question 242:

  A systems engineer is adding a new 1GB XFS filesystem that should be temporarily mounted under /ops/app. Which of the following is the correct list of commands to achieve this goal?

  

  A. Option A

  B. Option B

  C. Option C

  D. Option D

  Correct Answer: D

  Explanation: The list of commands in option D is the correct way to achieve the goal. The commands are as follows:

  fallocate -l 1G /ops/app.img creates a 1GB file named app.img under the /ops directory.

  mkfs.xfs /ops/app.img formats the file as an XFS filesystem. mount -o loop /ops/app.img /ops/app mounts the file as a loop device under the /ops/app directory. The other options are incorrect because they either use the wrong commands (dd

  or truncate instead of fallocate), the wrong options (-t or - f instead of -o), or the wrong order of arguments (/ops/app.img /ops/app instead of /ops/app /ops/app.img). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter

  10: Managing Storage, pages 323-324.

• Question 243:

  A Linux administrator was tasked with deleting all files and directories with names that are contained in the sobelete.txt file. Which of the following commands will accomplish this task?

  A. xargs -f cat toDelete.txt -rm

  B. rm -d -r -f toDelete.txt

  C. cat toDelete.txt | rm -frd

  D. cat toDelete.txt | xargs rm -rf

  Correct Answer: D

  Explanation: The command cat toDelete.txt | xargs rm -rf will delete all files and directories with names that are contained in the toDelete.txt file. The cat command reads the file and outputs its contents to the standard output. The | operator

  pipes the output to the next command. The xargs command converts the output into arguments for the next command. The rm -rf command removes the files and directories recursively and forcefully. This is the correct way to accomplish the

  task. The other options are incorrect because they either use the wrong options (-f instead of -a for xargs), the wrong arguments (toDelete.txt instead of toDelete.txt filename for rm), or the wrong commands (rm instead of xargs). References:

  CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 11:

  Managing Files and Directories, pages 349-350.

• Question 244:

  A systems administrator made some changes in the ~/.bashrc file and added an alias command. When the administrator tried to use the alias command, it did not work. Which of the following should be executed FIRST?

  A. source ~/.bashrc

  B. read ~/.bashrc

  C. touch ~/.bashrc

  D. echo ~/.bashrc

  Correct Answer: A

  Explanation: The command source ~/.bashrc should be executed first to use the alias command. The source command reads and executes commands from a file in the current shell environment. The ~/.bashrc file is a configuration file that contains commands and aliases that are executed when a new bash shell is started. The administrator made some changes in the ~/.bashrc file and added an alias command, but the changes are not effective until the file is sourced or a new shell is started. The command source ~/.bashrc will reload the file and make the alias command available. The other options are incorrect because they either do not execute the commands in the file (read, touch, or echo) or do not affect the current shell environment (read or echo). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter

  9: Working with the Linux Shell, page 295.

• Question 245:

  A systems administrator detected corruption in the /data filesystem. Given the following output: Which of the following commands can the administrator use to best address this issue?

  

  A. umount /data mkfs . xfs /dev/sclcl mount /data

  B. umount /data xfs repair /dev/ sdcl mount /data

  C. umount /data fsck /dev/ sdcl mount / data

  D. umount /data pvs /dev/sdcl mount /data

  Correct Answer: B

  The xfs repair command is used to check and repair an XFS filesystem, which is the type of filesystem used for the /data partition, as shown in the output. The administrator needs to unmount the /data partition before running the xfs repair command on it, and then mount it back after the repair is done. For example: umount /data; xfs_repair /dev/sdcl; mount /data. The mkfs.xfs command is used to create a new XFS filesystem, which would erase all the data on the partition. The fsck command is used to check and repair other types of filesystems, such as ext4, but not XFS. The pvs command is used to display information about physical volumes in a logical volume manager (LVM) setup, which is not relevant for this issue.

• Question 246:

  A Linux administrator provisioned a new web server with custom administrative permissions for certain users. The administrator receives a report that user1 is unable to restart the Apache web service on this server. The administrator reviews the following output:

  [ root@server ] # id user1

  UID=1011 (user1) gid=1011 (USER1) groups=1011 (user1), 101 (www-data), 1120 (webadmin)

  [ root@server ] # cat /etc/sudoers.d/custom.conf

  user1 ALL=/usr/sbin/systemctl start httpd, /usr/sbin/systemctl stop httpd

  webadmin ALL=NOPASSWD: /etc/init.d.httpd restart, /sbin/service httpd restart, /usr/sbin/apache2ctl restart

  #%wheel ALL=(ALL) NOPASSWD: ALL

  Which of the following would most likely resolve the issue while maintaining a least privilege security model?

  A. User1 should be added to the wheel group to manage the service.

  B. User1 should have "NOPASSWD:" after the "ALL=" in the custom. conf.

  C. The wheel line in the custom. conf file should be uncommented.

  D. Webadmin should be listed as a group in the custom. conf file.

  Correct Answer: D

  The custom.conf file grants sudo privileges to user1 and webadmin for managing the Apache web service, but it uses different commands for each of them. User1 is allowed to use systemctl to start and stop the httpd service, while webadmin is allowed to use init.d, service, or apache2ctl to restart the httpd service. However, the user1 is unable to restart the service, only start and stop it. To fix this, user1 should be able to use the same commands as webadmin, which can be achieved by listing webadmin as a group in the custom.conf file, using the syntax %groupname. This way, user1 will inherit the sudo privileges of the webadmin group, and be able to restart the Apache web service without compromising the least privilege security model. References Sudo and Sudoers Configuration | Servers for Hackers, section "Groups" Chapter 12. Managing sudo access - Red Hat Customer Portal, section "12.1. Configuring sudo access for users and groups"

• Question 247:

  Which of the following is a function of a bootloader?

  A. It initializes all the devices that are required to load the OS.

  B. It mounts the root filesystem that is required to load the OS.

  C. It helps to load the different kernels to initiate the OS startup process.

  D. It triggers the start of all the system services.

  Correct Answer: C

  Explanation: A function of a bootloader is to help load the different kernels to initiate the OS startup process. A bootloader is a program that runs when the system is powered on and prepares the system for booting the OS. A bootloader can load different kernels, which are the core components of the OS, and pass the control to the selected kernel. A bootloader can also provide a menu for the user to choose which kernel or OS to boot. This is a correct function of a bootloader. The other options are incorrect because they are either functions of the kernel (initialize devices or mount root filesystem) or functions of the init system (trigger the start of system services). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 8: Managing the Linux Boot Process, page 265.

• Question 248:

  A systems administrator made some unapproved changes prior to leaving the company. The newly hired administrator has been tasked with revealing the system to a compliant state. Which of the following commands will list and remove the correspondent packages?

  A. dnf list and dnf remove last

  B. dnf remove and dnf check

  C. dnf info and dnf upgrade

  D. dnf history and dnf history undo last

  Correct Answer: D

  Explanation: The commands that will list and remove the corresponding packages are dnf history and dnf history undo last. The dnf history command will display a list of all transactions performed by dnf, such as installing, updating, or removing packages. Each transaction has a unique ID, a date and time, an action, and a number of altered packages. The dnf history undo last command will undo the last transaction performed by dnf, meaning that it will reverse all package changes made by that transaction. For example, if the last transaction installed some packages, dnf history undo last will remove them. The other options are not correct commands for listing and removing corresponding packages. The dnf list command will display a list of available packages in enabled repositories, but not the packages installed by dnf transactions. The dnf remove command will remove specified packages from the system, but not all packages from a specific transaction. The dnf info command will display detailed information about specified packages, but not about dnf transactions. The dnf upgrade command will upgrade all installed packages to their latest versions, but not undo any package changes. References: Handling package management history; dnf(8) - Linux manual page

• Question 249:

  A systems administrator is notified that the mysqld process stopped unexpectedly. The systems administrator issues the following command:

  sudo grep -i -r `out of memory' /var/log

  The output of the command shows the following:

  kernel: Out of memory: Kill process 9112 (mysqld) score 511 or sacrifice child.

  Which of the following commands should the systems administrator execute NEXT to troubleshoot this issue? (Select two).

  A. free -h

  B. nc -v 127.0.0.1 3306

  C. renice -15 $( pidof mysql )

  D. lsblk

  E. killall -15

  F. vmstat -a 1 4

  Correct Answer: AF

  Explanation: The free -h command can be used to check the amount of free and used memory in the system in a human-readable format. This can help to troubleshoot the issue of mysqld being killed due to out of memory. The vmstat -a 1 4 command can be used to monitor the system's virtual memory statistics, such as swap usage, paging activity, and memory faults, every one second for four times. This can help to identify any memory pressure or performance issues that may cause out of memory errors. The nc -v 127.0.0.1 3306 command would attempt to connect to the MySQL server on port 3306 and display any diagnostic messages, but this would not help to troubleshoot the memory issue. The renice -15 $( pidof mysql ) command would change the priority of the mysql process to -15, but this would not prevent it from being killed due to out of memory. The lsblk command would display information about block devices, not memory usage. The killall -15 command would send a SIGTERM signal to all processes with a matching name, but this would not help to troubleshoot the memory issue. References: [CompTIA Linux+ (XK0-005) Certification Study Guide], Chapter 15: Managing Memory and Process Execution, pages 468-469.

• Question 250:

  A Linux administrator has logged in to a server for the first time and needs to know which services are allowed through the firewall. Which of the following options will return the results for which the administrator is looking?

  A. firewall-cmd --get-services

  B. firewall-cmd --check-config

  C. firewall-cmd --list-services

  D. systemct1 status firewalld

  Correct Answer: C

  Explanation: The firewall-cmd --list-services command will return the results for which the administrator is looking. This command will list all services that are allowed through the firewall in the default zone or a specified zone. A service is a predefined set of ports and protocols that can be enabled or disabled by firewalld. The firewall-cmd --get-services command will list all available services that are supported by firewalld, not only those that are allowed through the firewall. The firewall-cmd --check-config command will check if firewalld configuration files are valid, not list services. The systemct1 status firewalld command will display information about the firewalld service unit, such as its state, PID, memory usage, and logs, not list services. References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 18: Securing Linux Systems, page 543.