CompTIA XK0-005 Online Practice Questions and Exam Preparation

CompTIA XK0-005 Online Questions & Answers

• Question 181:

  The group owner of the / home/ test directory would like to preserve all group permissions on files created in the directory. Which of the following commands should the group owner execute?

  A. chmod g+s /home/test
  B. chgrp test /home/test
  C. chmod 777 /home/test
  D. chown --hR test /home/test
  A. chmod g+s /home/test

  ---

  Explanation

  The correct answer is A. chmod g+s /home/test

  This command will set the setgid bit on the /home/test directory, which means that any file or subdirectory created in the directory will inherit the group ownership of the directory. This way, the group permissions on files created in the directory will be preserved. The chmod command is used to change the permissions of files and directories. The g+s option is used to set the setgid bit for the group.

  The other options are incorrect because:

  B. chgrp test /home/test

  This command will change the group ownership of the /home/test directory to test, but it will not affect the group ownership of files created in the directory. The chgrp command is used to change the group of files and directories. The test /home/test arguments are used to specify the new group and the target directory.

  C. chmod 777 /home/test

  This command will give read, write, and execute permissions to everyone (owner, group, and others) on the /home/test directory, but it will not affect the group ownership or permissions of files created in the directory. The chmod command is used to change the permissions of files and directories. The 777 argument is an octal number that represents the permissions in binary form.

  D. chown -hR test /home/test

  This command will change the owner and group of the /home/test directory and all its contents recursively to test, but it will not preserve the original group permissions on files created in the directory. The chown command is used to change the owner and group of files and directories. The -hR option is used to affect symbolic links and operate on all files and directories recursively. The test /home/test arguments are used to specify the new owner and group and the target directory.

  References:

  How to Set File Permissions Using chmod

  How to Use Chmod Command in Linux with Examples

  How to Use Chown Command in Linux with Examples

  [How to Use Chgrp Command in Linux with Examples]

• Question 182:

  A systems administrator receives reports that several virtual machines in a host are responding slower than expected. Upon further investigation, the administrator obtains the following output from one of the affected systems:

  

  Which of the following best explains the reported issue?

  A. The physical host is running out of CPU resources, leading to insufficient CPU time being allocated to virtual machines.
  B. The physical host has enough CPU cores, leading to users running more processes to compensate for the slower response times.
  C. The virtual machine has enough CPU cycles, leading to the system use percentage being higher than expected.
  D. The virtual machine is running out of CPU resources, leading to users experiencing longer response times.
  D. The virtual machine is running out of CPU resources, leading to users experiencing longer response times.

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  Explanation

  Based on the output from one of the affected systems, the best explanation for the reported issue is that the virtual machine is running out of CPU resources, leading to users experiencing longer response times (D). The output shows that the system use percentage is very high (57.85%), indicating that the virtual machine is using most of its CPU cycles for system processes. This leaves little CPU time for user processes, which results in slower performance. The other explanations are not supported by the output or are contradictory.

  References: [CompTIA Linux+ Study Guide], Chapter 8: Optimizing Linux Performance, Section: Monitoring CPU Usage [How to Interpret CPU Usage Statistics]

• Question 183:

  A Linux administrator generated a list of users who have root-level command-line access to the Linux server to meet an audit requirement. The administrator analyzes the following /etc/passwd and /etc/sudoers files: $ cat /etc/passwd root:x: 0:0: :/home/root: /bin/bash lee: x: 500: 500: :/home/lee:/bin/tcsh mallory:x: 501:501: :/root:/bin/bash eve:x: 502: 502: /home/eve:/bin/nologin

  carl:x:0:503: :/home/carl:/bin/sh bob:x: 504: 504: : /home/bob:/bin/ksh alice:x: 505:505: :/home/alice:/bin/rsh $ cat /etc/sudoers Cmnd_Alias SHELLS = /bin/tcsh, /bin/sh, /bin/bash Cmnd_Alias SYSADMIN = /usr/sbin/tcpdump ALL = (ALL) ALL ALL = NOPASSWD: SYSADMIN Which of the following users, in addition to the root user, should be listed in the audit report as having root-level command-line access? (Select two).

  A. Carl
  B. Lee
  C. Mallory
  D. Eve
  E. Bob
  F. Alice
  A. Carl
  C. Mallory

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  Explanation

  The users who have root-level command-line access are those who have either the same user ID (UID) as root, which is 0, or the ability to run commands as root using sudo. Based on the /etc/passwd and /etc/sudoers files, the users who meet these criteria are: Carl: Carl has the same UID as root, which is 0, as shown in the /etc/passwd file. This means that Carl can log in as root and execute any command with root privileges1 Mallory: Mallory has the ability to run commands as root using sudo, as shown in the /etc/sudoers file. The line ALL = (ALL) ALL means that any user can run any command as any other user, including root, by using sudo. Mallory can also use the root shell /bin/bash as her login shell, as shown in the /etc/passwd file2 Therefore, the correct answer is A and

  C. Lee, Eve, Bob, and Alice do not have root-level command-line access because they have different UIDs from root and they cannot use sudo to run commands as root. Lee can only use sudo to run the commands listed in the Cmnd_Alias SHELLS, which are /bin/tcsh, /bin/sh, and /bin/bash. Eve cannot log in at all because her login shell is /bin/nologin. Bob and Alice can only use sudo to run the command /usr/sbin/tcpdump without a password, as specified by the Cmnd_Alias SYSADMIN and the line ALL = NOPASSWD: SYSADMIN2

• Question 184:

  A systems administrator is compressing old log files in order to save space. Which of the following commands will allow the administrator to save the most space?

  A. bzip2
  B. xz
  C. tar
  D. gzip
  B. xz

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  Explanation

• Question 185:

  A junior developer is unable to access an application server and receives the following output:

  

  The systems administrator investigates the issue and receives the following output:

  

  Which of the following commands will help unlock the account?

  A. Pam_tally2 --user=dev2 ---quiet
  B. pam_ tally2 --user=dev2
  C. pam_tally2 --user+dev2 ---quiet
  D. pam_tally2 --user=dev2 ---reset
  D. pam_tally2 --user=dev2 ---reset

  ---

  Explanation

  To unlock an account that has been locked due to login failures, the administrator can use the command pam_tally2 --user=dev2 --reset (D). This will reset the failure counter for the user "dev2" and allow the user to log in again. The other commands will not unlock the account, but either display or increase the failure count.

  References:

  [CompTIA Linux+ Study Guide], Chapter 4: Managing Users and Groups, Section:

  Locking Accounts with pam_tally2

  [How to Lock and Unlock User Account in Linux]

• Question 186:

  A Linux system is having issues. Given the following outputs:

  # dig @192.168.2.2 mycomptiahost

  ; << >> DiG 9.9.4-RedHat-9.9.4-74.el7_6.1 << >> @192.168.2.2 mycomptiahost

  ; (1 server found)

  ;; global options: +cmd

  ;; connection timed out; no servers could be reached

  # nc -v 192.168.2.2 53

  Ncat: Version 7.70 ( https://nmap.org/ncat )

  Ncat: Connection timed out.

  # ping 192.168.2.2

  PING 192.168.2.2 (192.168.2.2) 56(84) bytes of data.

  64 bytes from 192.168.2.2: icmp_seq=1 ttl=117 time=4.94 ms

  64 bytes from 192.168.2.2: icmp_seq=2 ttl=117 time=10.5 ms

  Which of the following best describes this issue?

  A. The DNS host is down.
  B. The name mycomptiahost does not exist in the DNS.
  C. The Linux engineer is using the wrong DNS port.
  D. The DNS service is currently not available or the corresponding port is blocked.
  D. The DNS service is currently not available or the corresponding port is blocked.

  ---

  Explanation

  The ping command shows that the Linux system can reach the DNS server at 192.168.2.2, so the DNS host is not down. The dig and nc commands show that the Linux system cannot connect to the DNS server on port 53, which is the standard port for DNS queries. This means that either the DNS service is not running on the DNS server, or there is a firewall or network device blocking the port 53 traffic. Therefore, the DNS service is currently not available or the corresponding port is blocked.References1: How To Troubleshoot DNS Client Issues in Linux - RootUsers2: 6 Best Tools to Troubleshoot DNS Issues in Linux - Tecmint3: How To Troubleshoot DNS in Linux - OrcaCore4: Fixing DNS Issues in Ubuntu 20.04 | DeviceTests

• Question 187:

  A new disk was presented to a server as /dev/ sdd. The systems administrator needs to check if a partition table is on that disk. Which of the following commands can show this information?

  A. Isscsi
  B. fdisk
  C. blkid
  D. partprobe
  B. fdisk

  ---

  Explanation

  The command that can be used to check if a partition table is on a disk is fdisk. The fdisk command can display, create, delete, and modify partitions on a disk. To show the partition table of a disk, the administrator can use fdisk -l /dev/sdd (B).

  References:

  [CompTIA Linux+ Study Guide], Chapter 5: Managing Filesystems and Logical Volumes, Section: Partitioning Disks

  [How to Use Fdisk Command in Linux]

• Question 188:

  A Linux systems administrator has applied the necessary configuration to allow both HTTP and HTTPS through the firewall. However, the host is not responding on either HTTP or HTTPS. Given the output below, what is the issue?

  firewall-cmd --list-all-zones

  public (active)

  ...

  services: ssh

  ...

  internal

  ...

  services: http https ssh

  Which of the following best describes the reason the system is not responding on HTTP or HTTPS?

  A. The incorrect rules were configured on the firewall
  B. The interface has the incorrect routes configured
  C. The rules were added to the wrong zone
  C. The rules were added to the wrong zone

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  Explanation

• Question 189:

  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
  D. dnf history and dnf history undo last

  ---

  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 190:

  A user is unable to log on to a Linux workstation. The systems administrator executes the following command:

  cat /etc/shadow | grep user1

  The command results in the following output:

  user1 :! $6$QERgAsdvojadv4asdvaarC/9dj34GdafGVaregmkdsfa:18875:0:99999:7 :::

  Which of the following should the systems administrator execute to fix the issue?

  A. chown -R userl:user1 /home/user1
  B. sed -i '/ ::: / :: /g' /etc/shadow
  C. chgrp user1:user1 /home/user1
  D. passwd -u user1
  D. passwd -u user1

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  Explanation

  The output shows that the user1 account has a locked password, indicated by the exclamation point (!) in the second field of the /etc/shadow file1. To unlock the password and allow the user to log in, the systems administrator should use the passwd command with the -u (unlock) option2.

  References: 1: Understanding the /etc/shadow File 2: How To Use The Passwd Command In Linux