CompTIA XK0-005 Online Practice Questions and Exam Preparation

CompTIA XK0-005 Online Questions & Answers

• Question 351:

  A cloud engineer is installing packages during VM provisioning. Which of the following should the engineer use to accomplish this task?

  A. Cloud-init
  B. Bash
  C. Docker
  D. Sidecar
  A. Cloud-init

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  Explanation

  The cloud engineer should use cloud-init to install packages during VM provisioning. Cloud-init is a tool that allows the customization of cloud instances at boot time. Cloud-init can perform various tasks, such as setting the hostname, creating users, installing packages, configuring network, and running scripts. Cloud-init can work with different cloud platforms and Linux distributions. This is the correct tool to accomplish the task. The other options are incorrect because they are either not suitable for cloud provisioning (Bash or Docker) or not a tool but a design pattern (Sidecar).

  References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 19:

  Managing Cloud and Virtualization Technologies, page 563.

• Question 352:

  Which of the following describes how a user's public key is used during SSH authentication?

  A. The user's public key is used to hash the password during SSH authentication.
  B. The user's public key is verified against a list of authorized keys. If it is found, the user is allowed to log in.
  C. The user's public key is used instead of a password to allow server access.
  D. The user's public key is used to encrypt the communication between the client and the server.
  B. The user's public key is verified against a list of authorized keys. If it is found, the user is allowed to log in.

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  Explanation

• Question 353:

  A systems administrator requires that all files that are created by the user named web have read-only permissions by the owner. Which of the following commands will satisfy this requirement?

  A. chown web:web /home/web
  B. chmod -R 400 /home/web
  C. echo "umask 377" >> /home/web/.bashrc
  D. setfacl read /home/web
  C. echo "umask 377" >> /home/web/.bashrc

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  Explanation

  The command that will satisfy the requirement of having all files that are created by the user named web have read-only permissions by the owner is echo "umask 377" >> /home/web/.bashrc. This command will append the umask 377 command to the end of the .bashrc file in the web user's home directory. The .bashrc file is a shell script that is executed whenever a new interactive shell session is started by the user. The umask command sets the file mode creation mask, which determines the default permissions for newly created files or directories by subtracting from the maximum permissions (666 for files and 777 for directories). The umask 377 command means that the user does not want to give any permissions to the group or others (3 = 000 in binary), and only wants to give read permission to the owner (7 - 3 = 4 = 100 in binary). Therefore, any new file created by the web user will have read-only permission by the owner (400) and no permission for anyone else.

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

  8: Managing Users and Groups; Umask Command in Linux | Linuxize

• Question 354:

  An administrator wants to execute a long-running script in the terminal while troubleshooting another issue. Which of the following options will achieve this goal?

  A. bash script.sh and
  B. source script.sh
  C. sh script.sh | jobs
  D. nice -10 ./script.sh
  A. bash script.sh and

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  Explanation

  Running a command with and at the end sends it to the background, allowing the administrator to continue using the terminal for other tasks while the script runs. This is useful for long-running scripts that do not require immediate attention but need to keep running.

  Linux Background Jobs

• Question 355:

  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
  D. cat toDelete.txt | xargs rm -rf

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  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 356:

  Which of the following actions is required to establish a passwordless SSH authentication?

  A. Copy the private SSH key to the remote server.
  B. Copy the public and private keys to the remote server.
  C. Generate public and private keys on the remote server.
  D. Copy the public SSH key to the remote server.
  D. Copy the public SSH key to the remote server.

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  Explanation

  Passwordless SSH authentication is achieved by copying the public SSH key (id_rsa.pub) from the local system to the remote server's ~/.ssh/authorized_keys file.

  Option D (Correct): This ensures that the remote server can authenticate the client using the corresponding private key.

  Option A: Incorrect, as copying the private key is a security risk.

  Option B: Incorrect, only the public key should be copied.

  Option C: Incorrect, key generation should be done on the client, not the server.

  Exam C

• Question 357:

  A systems administrator is encountering performance issues. The administrator runs 3 commands with the following output

  

  The Linux server has the following system properties

  CPU: 4 vCPU Memory: 50GB

  Which of the following accurately describes this situation?

  A. The system is under CPU pressure and will require additional vCPUs
  B. The system has been running for over a year and requires a reboot.
  C. Too many users are currently logged in to the system
  D. The system requires more memory
  A. The system is under CPU pressure and will require additional vCPUs

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  Explanation

  Based on the output of the image sent by the user, the system is under CPU pressure and will require additional vCPUs. The output shows that there are four processes running upload.sh scripts that are consuming a high percentage of CPU time (99.7%, 99.6%, 99.5%, and 99.4%). The output also shows that the system has only 4 vCPUs, which means that each process is using almost one entire vCPU. This indicates that the system is struggling to handle the CPU load and may experience performance issues or slowdowns. Adding more vCPUs to the system would help to alleviate the CPU pressure and improve the system performance. The system has not been running for over a year, as the uptime command shows that it has been up for only 1 day, 2 hours, and 13 minutes. The number of users logged in to the system is not relevant to the performance issue, as they are not consuming significant CPU resources. The system does not require more memory, as the free command shows that it has plenty of available memory (49 GB total, 48 GB free).

  References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 15: Managing Memory and Process Execution, pages 468-469.

• Question 358:

  A Linux engineer receives reports that files created within a certain group are being modified by users who are not group members. The engineer wants to reconfigure the server so that only file owners and group members can modify new files by default. Which of the following commands would accomplish this task?

  A. chmod 775
  B. umask. 002
  C. chactr -Rv
  D. chown -cf
  B. umask. 002

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  Explanation

  The command umask 002 will accomplish the task of reconfiguring the server so that only file owners and group members can modify new files by default. The umask command is a tool for setting the default permissions for new files and directories on Linux systems. The umask value is a four-digit octal number that represents the permissions that are subtracted from the default permissions. The default permissions for files are 666, which means read and write for owner, group, and others. The default permissions for directories are 777, which means read, write, and execute for owner, group, and others. The umask value consists of four digits: the first digit is for special permissions, such as setuid, setgid, and sticky bit; the second digit is for the owner permissions; the third digit is for the group permissions; and the fourth digit is for the others permissions. The umask value can be calculated by subtracting the desired permissions from the default permissions. For example, if the desired permissions for files are 664, which means read and write for owner and group, and read for others, then the umask value is 002, which is 666 - 664. The command umask 002 will set the umask value to 002, which will ensure that only file owners and group members can modify new files by default. This is the correct command to use to accomplish the task. The other options are incorrect because they either do not set the default permissions for new files (chmod 775 or chown - cf) or do not exist (chattr -Rv).

  References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 11: Managing File Permissions and Ownership, page 349.

• Question 359:

  A Linux administrator is tasked with moving files in a database server. The administrator must not overwrite any existing files. Which of the following commands would indicate that the file already exists?

  A. mv-ifilename/tmp/backup
  B. mv-bfilename/tmp/backup
  C. mv-nfilename/tmp/backup
  D. mv-ffilename/tmp/backup
  A. mv-ifilename/tmp/backup

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  Explanation

  The -i option stands for 'interactive' and it prompts before overwriting any existing files. This ensures that no existing files are accidentally overwritten during the move operation.

• Question 360:

  A Linux systems administrator needs to add additional code to code that resides within a repository without changing the original code. Once completed, the additional code will be merged into the main branch. Which of the following commands should the administrator use first?

  A. git push
  B. git rebase
  C. git tag
  D. git clone
  B. git rebase

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  Explanation