CompTIA XK0-005 Online Practice Questions and Exam Preparation

CompTIA XK0-005 Online Questions & Answers

• Question 111:

  One leg of an LVM-mirrored volume failed due to the underlying physical volume, and a systems administrator is troubleshooting the issue. The following output has been provided:

  

  Given this scenario, which of the following should the administrator do to recover this volume?

  A. Reboot the server. The volume will automatically go back to linear mode.
  B. Replace the failed drive and reconfigure the mirror.
  C. Reboot the server. The volume will revert to stripe mode.
  D. Recreate the logical volume.
  B. Replace the failed drive and reconfigure the mirror.

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  Explanation

  The administrator should replace the failed drive and reconfigure the mirror to recover the volume. The LVM (Logical Volume Manager) is a tool for managing disk space on Linux systems. The LVM allows the administrator to create logical volumes that span across multiple physical volumes, such as hard disks or partitions. The LVM also supports different types of logical volumes, such as linear, striped, or mirrored. A mirrored logical volume is a type of logical volume that creates a copy of the data on another physical volume, providing redundancy and fault tolerance. The output shows that the logical volume is mirrored and that one leg of the mirror has failed due to the underlying physical volume. This means that one of the physical volumes that contains the data of the logical volume is damaged or missing. This can cause data loss and performance degradation. The administrator should replace the failed drive and reconfigure the mirror to recover the volume. The administrator should identify the failed physical volume by using commands such as pvdisplay, vgdisplay, or lvdisplay. The administrator should then remove the failed physical volume from the volume group by using the vgreduce command. The administrator should then install a new drive and create a new physical volume by using the pvcreate command. The administrator should then add the new physical volume to the volume group by using the vgextend command. The administrator should then reconfigure the mirror by using the lvconvert command. The administrator should replace the failed drive and reconfigure the mirror to recover the volume. This is the correct answer to the question. The other options are incorrect because they either do not recover the volume (reboot the server. The volume will automatically go back to linear mode or reboot the server. The volume will revert to stripe mode) or do not preserve the data of the volume (recreate the logical volume).

  References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 10: Managing Storage, pages 333-334.

• Question 112:

  A user is attempting to log in to a Linux server that has Kerberos SSO ena-bled. Which of the following commands should the user run to authenticate and then show the ticket grants? (Select TWO).

  A. kinit
  B. klist
  C. kexec
  D. kioad
  E. pkexec
  F. realm
  A. kinit
  B. klist

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  Explanation

  The following commands can help the user to authenticate and show the ticket grants using Kerberos SSO on a Linux server:

  kinit: This command obtains and caches an initial ticket-granting ticket (TGT) for the user from the Kerberos key distribution center (KDC). The user needs to enter their password or use a keytab file to authenticate1. klist: This command lists the cached tickets, including the TGT and any service tickets, for the user. It also shows the expiration time and flags for each ticket2. For example, the user can run the following commands to log in and view their tickets:

  $ kinit username@REALM

  Password for username@REALM:

  $ klist

  Ticket cache: FILE:/tmp/krb5cc_1000

  Default principal: username@REALM

  Valid starting Expires Service principal

  04/06/2023 16:06:59 04/07/2023 02:06:59 krbtgt/REALM@REALM renew until 04/13/2023 16:06:59

  References:

  kinit(1) - Linux man page, section "Description".

  klist(1) - Linux man page, section "Description".

• Question 113:

  A systems administrator received a report about issues with a Linux system. Given the following output:

  

  Which of the following is the best command to use to fix this issue?

  A. mkfs.xfs /var
  B. rm -rf /var/*
  C. lvextend -L +5G -r /dev/mapper/rootvg-varlv
  D. lvresize -L +2G -r /dev/mapper/rootvg-rootlv
  C. lvextend -L +5G -r /dev/mapper/rootvg-varlv

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  Explanation

• Question 114:

  A user (userA) has reported issues while logging in to the system. The following output has been provided: bash Could not chdir to home directory /home/userA: Permission denied -bash: /home/userA/.bash_profile: Permission denied # cat /etc/passwd | grep userA userA:x:1234:3400:userA account:/home/userA/:/bin/bash # passwd -S userA userA PS 2022-10-17 1 99999 0 (Password set. SHA512 crypt.) # groups userA

  admin dev usergrp # ls -lth /home/ drwx------ 7 root admin 9 Jan 17 2019 userA drwxr-xr-x 4 userC app 9 Jan 23 2020 userC Which of the following describes the issue userA is having?

  A. The password for userA is not set
  B. The group for userA is not assigned correctly
  C. The account password for userA has expired
  D. The assigned home directory is not owned by userA
  D. The assigned home directory is not owned by userA

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  Explanation

  The issue occurs because the home directory /home/userA is owned by root, not by userA, as seen from the ls -lth /home output. In Linux, the user must have ownership of their home directory to log in and access their files properly. To fix this, the administrator must change ownership using chown userA:userA /home/userA.

• Question 115:

  HotsPot

  A new drive was recently added to a Linux system. Using the environment and tokens provided, complete the following tasks:

  Create an appropriate device label.

  Format and create an ext4 file system on the new partition. The current working directory is /.

  

  

• Question 116:

  An administrator needs to increase the system priority of a process with PID 2274. Which of the following commands should the administrator use to accomplish this task?

  A. renice --n --15 2274
  B. nice -15 2274
  C. echo "--15" > /proc/PID/2274/priority
  D. ps --ef I grep 2274
  A. renice --n --15 2274

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  Explanation

  The renice command is used to change the priority of a running process by specifying its PID and the new nice value. The -n flag indicates the amount of change in the nice value, which can be positive or negative. A lower nice value means a higher priority, so -15 will increase the priority of the process with PID 2274. The administrator needs to have root privileges to do this.

  References:

  The renice command is listed as one of the commands to manipulate process priority in the web search result 1. The renice command is also explained with examples in the web search result 2. The CompTIA Linux+ Certification Exam Objectives mention that the candidate should be able to "manage process execution priorities" as part of the System Operation and Maintenance domain1.

• Question 117:

  An administrator wants to copy files from /opt/tools to the home directory at /home/admin. Which of the following should the administrator run?

  A. mkdir -p /home/admin/tools
  B. cp -R /opt/tools ~
  C. cd /opt/tools; rsync /home/admin
  D. scp /opt/tools localhost:/
  B. cp -R /opt/tools ~

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  Explanation

• Question 118:

  A Linux systems administrator is working to obtain the installed kernel version of several hundred systems. Which of the following utilities should the administrator use for this task?

  A. Ansible
  B. Git
  C. Docker
  D. Bash
  A. Ansible

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  Explanation

  Ansible is an open-source automation tool that can manage multiple systems simultaneously. Using an Ansible playbook, the administrator can run commands across several servers to obtain the installed kernel version efficiently. A simple ansible all -m command -a "uname -r" will retrieve the kernel version from all target systems.

• Question 119:

  A database administrator requested the installation of a custom database on one of the servers. Which of the following should the Linux administrator configure so the requested packages can be installed?

  A. /etc/yum.conf
  B. /etc/ssh/sshd.conf
  C. /etc/yum.repos.d/db.repo
  D. /etc/resolv.conf
  C. /etc/yum.repos.d/db.repo

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  Explanation

  The Linux administrator should configure /etc/yum.repos.d/db.repo so that the requested packages can be installed. This file defines a custom repository for yum, which is a package manager for RPM-based systems. The file should contain information such as the name, baseurl, gpgcheck, and enabled options for the repository. By creating this file and enabling the repository, the administrator can use yum to install packages from the custom repository. The /etc/yum.conf file is the main configuration file for yum, but it does not define repositories. The /etc/ssh/sshd.conf file is the configuration file for sshd, which is a daemon that provides secure shell access to remote systems. The /etc/resolv.conf file is the configuration file for DNS resolution, which maps domain names to IP addresses.

  References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 19: Managing Packages and Software, page 559.

• Question 120:

  Which of the following actions are considered good security practices when hardening a Linux server? (Select two).

  A. Renaming the root account to something else
  B. Removing unnecessary packages
  C. Changing the default shell to /bin/csh
  D. Disabling public key authentication
  E. Disabling the SSH root login possibility
  F. Changing the permissions on the root filesystem to 600
  B. Removing unnecessary packages
  E. Disabling the SSH root login possibility

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  Explanation

  Some good security practices when hardening a Linux server are:

  Removing unnecessary packages (B) to reduce the attack surface and eliminate potential vulnerabilities

  Disabling the SSH root login possibility (E) to prevent unauthorized access and brute-force attacks on the root account

  References:

  [CompTIA Linux+ Study Guide], Chapter 9: Securing Linux, Section: Hardening Linux

  [How to Harden Your Linux Server]