CompTIA XK0-005 Online Practice Questions and Exam Preparation

CompTIA XK0-005 Online Questions & Answers

• Question 291:

  A user reported issues when trying to log in to a Linux server. The following outputs were received:

  Given the outputs above. which of the following is the reason the user is una-ble to log in to the server?

  A. User1 needs to set a long password.
  B. User1 is in the incorrect group.
  C. The user1 shell assignment incorrect.
  D. The user1 password is expired.
  D. The user1 password is expired.

  ---

  Explanation

  The user1 password is expired. This can be inferred from the output of the chage -l user1 command, which shows the password expiration information for user1. The output shows that the password expired on 2020-10-01, and the account expired on 2020-10-08. This means that user1 cannot log in to the server unless the password and account are reactivated by the system administrator. The other options are not correct based on the outputs above. User1 does not need to set a long password, because the output of the passwd -S user1 command shows that the password has a minimum length of 5 characters, which is met by user1's password. User1 is not in the incorrect group, because the output of the groups user1 command shows that user1 belongs to the app group, which is presumably the correct group for accessing the server. The user1 shell assignment is not incorrect, because the output of the grep user1 /etc/passwd command shows that user1 has /bin/bash as the default shell, which is a valid and common shell for Linux users.

• Question 292:

  A DevOps engineer is working on a local copy of a Git repository. The engineer would like to switch from the main branch to the staging branch but notices the staging branch does not exist. Which of the following Git commands should the engineer use to perform this task?

  A. git branch --m staging
  B. git commit --m staging
  C. git status --b staging
  D. git checkout --b staging
  D. git checkout --b staging

  ---

  Explanation

  The correct answer is

  D. git checkout -b staging

  This command will create a new branch named staging and switch to it. The git checkout command is used to switch between branches or restore files from a specific branch. The - b option is used to create a new branch if it does not exist.

  For example, git checkout -b staging will create and switch to the staging branch.

  The other options are incorrect because:

  A. git branch -m staging This command will rename the current branch to staging, not switch to it. The git branch command is used to list, create, or delete branches. The -m option is used to rename a branch. For example, git branch -m staging will rename the current branch to staging.

  B. git commit -m staging This command will commit the changes in the working tree to the current branch with a message of staging, not switch to it. The git commit command is used to record changes to the repository. The -m option is used to specify a commit message. For example, git commit -m staging will commit the changes with a message of staging.

  C. git status -b staging This command will show the status of the working tree and the current branch, not switch to it. The git status command is used to show the state of the working tree and the staged changes. The -b option is used to show the name of the current branch. However, this option does not take an argument, so specifying staging after it will cause an error.

  References: Git - git-checkout Documentation Git Tutorial: Create a New Branch With Git Checkout Git Branching - Basic Branching and Merging

• Question 293:

  A Linux administrator was notified that a virtual server has an I/O bottleneck. The Linux administrator analyzes the following output:

  

  Given there is a single CPU in the sever, which of the following is causing the slowness?

  A. The system is running out of swap space.
  B. The CPU is overloaded.
  C. The memory is exhausted.
  D. The processes are paging.
  B. The CPU is overloaded.

  ---

  Explanation

  The slowness is caused by the CPU being overloaded. The iostat command shows that the CPU utilization is 100%, which means that there are more processes competing for CPU time than the CPU can handle. The other options are incorrect because:

  The system is not running out of swap space, as shown by the iostat command, which shows that there is no swap activity (si and so columns are zero). The memory is not exhausted, as shown by the free -m command, which shows that there is still available memory (avail column) and free buffer/cache memory (buff/cache column).

  The processes are not paging, as shown by the vmstat command, which shows that there are no major page faults (majflt column) and no swap activity (si and so columns).

  References: CompTIA Linux+ Study Guide, Fourth Edition, page

  417- 419, 424-425.

• Question 294:

  A systems administrator needs to remove a disk from a Linux server. The disk size is 500G, and it is the only one that size on that machine. Which of the following commands can the administrator use to find the corresponding device name?

  A. fdisk -V
  B. partprobe -a
  C. lsusb -t
  D. lsscsi -s
  D. lsscsi -s

  ---

  Explanation

  The lsscsi command can list the SCSI devices on the system, along with their size and device name. The -s option shows the size of each device. The administrator can look for the device that has a size of 500G and note its device name.

  See lsscsi(8) - Linux man page and How to check Disk Interface Types in Linux.References1:

  https://linux.die.net/man/8/lsscsi2: https://www.golinuxcloud.com/check-disk-type-linux/ An administrator accidentally installed the httpd RPM package along with several dependencies. Which of the following options is the best way for the administrator to revert the package installation?

  dnf clean all rpm -e httpd apt-get clean yum history undo last

  Answer: D

  The yum history undo last command will undo the last transaction, which in this case is the installation of the httpd RPM package and its dependencies. This will remove the packages that were installed and restore the previous state of the system. See How to undo or redo yum transactions and yum history.References1: https://www.redhat.com/sysadmin/undo- redo-yum-transactions2: https://man7.org/linux/man-pages/man8/yum.8.html#HISTORY

• Question 295:

  A Linux engineer needs to create a custom script, cleanup.sh, to run at boot as part of the system services. Which of the following processes would accomplish this task?

  A. Create a unit file in the /etc/default/ directory. systemct1 enable cleanup systemct1 is-enabled cleanup
  B. Create a unit file in the /etc/ske1/ directory. systemct1 enable cleanup systemct1 is-enabled cleanup
  C. Create a unit file in the /etc/systemd/system/ directory. systemct1 enable cleanup systemct1 is-enabled cleanup
  D. Create a unit file in the /etc/sysctl.d/ directory. systemct1 enable cleanup systemct1 is-enabled cleanup
  C. Create a unit file in the /etc/systemd/system/ directory. systemct1 enable cleanup systemct1 is-enabled cleanup

  ---

  Explanation

  The process that will accomplish the task of creating a custom script to run at boot as part of the system services is:

  Create a unit file in the /etc/systemd/system/ directory. A unit file is a configuration file that defines the properties and behavior of a systemd service. The systemd is a system and service manager that controls the startup and operation of Linux systems. The /etc/systemd/system/ directory is the location where the administrator can create and store custom unit files. The unit file should have a name that matches the name of the script, such as cleanup.service, and should contain the following sections and options:

  Run the command systemct1 enable cleanup. This command will enable the service and create the necessary symbolic links to start the service at boot. Run the command systemct1 is-enabled cleanup. This command will check the status of the service and confirm that it is enabled. This process will create a custom script, cleanup.sh, to run at boot as part of the system services. This is the correct process to use to accomplish the task. The other options are incorrect because they either use the wrong directory for the unit file (/etc/default/, /etc/skel/, or /etc/sysctl.d/) or do not create a unit file at all.

  References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 15:

  Managing System Services, pages 457-459.

• Question 296:

  Based on an organization's new cybersecurity policies, an administrator has been instructed to ensure that, by default, all new users and groups that are created fall within the specified values below.

  

  To which of the following configuration files will the required changes need to be made?

  A. /etc/login.defs
  B. /etc/security/limits.conf
  C. /etc/default/useradd
  D. /etc/profile
  A. /etc/login.defs

  ---

  Explanation

  The required changes need to be made to the /etc/login.defs configuration file. The /etc/login.defs file defines the default values for user and group IDs, passwords, shells, and other parameters for user and group creation. The file contains the directives UID_MIN, UID_MAX, GID_MIN, and GID_MAX, which set the minimum and maximum values for automatic user and group ID selection. The administrator can edit this file and change the values to match the organization's new cybersecurity policies. This is the correct file to modify to accomplish the task. The other options are incorrect because they either do not affect the user and group IDs (/etc/security/limits.conf or /etc/profile) or do not set the default values (/ etc/default/useradd).

  References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 15: Managing Users and Groups, page 463.

• Question 297:

  An operations engineer is planning to start a container running a PostgreSQL database. The engineer wants the container to start automatically at system startup, mount the /home/db directory as /var/lib/postgresql inside the container, and

  expose port 5432 to the OS.

  Which of the following commands should the engineer run to achieve this task?

  A. docker run -d --restart always -p 5432:5432 -v /home/db:/var/lib/postgresql postgresql:12
  B. docker run -d --restart -p 5432:5432 --volume /var/lib/postgresql:/home/db postgresql:12
  C. docker run -d --attach --platform 5432:5432 --volume /home/db:/var/lib/postgresql postgresql:12
  D. docker run -d --init --restart --publish 5432:5432 --workdir /home/db:/var/lib/postgresql postgresql:12
  A. docker run -d --restart always -p 5432:5432 -v /home/db:/var/lib/postgresql postgresql:12

  ---

  Explanation

  The command docker run -d --restart always -p 5432:5432 -v /home/db:/var/lib/postgresql postgresql:12 ensures that the PostgreSQL container is started in detached mode (-d), it restarts automatically on system startup (--restart always), mounts the host directory /home/db to /var/lib/postgresql, and exposes port 5432. This is a typical setup for running a database in a Docker container.

• Question 298:

  A Linux administrator copied a Git repository locally, created a feature branch, and committed some changes to the feature branch. Which of the following Git actions should the Linux administrator use to publish the changes to the main branch of the remote repository?

  A. rebase
  B. tag
  C. commit
  D. push
  D. push

  ---

  Explanation

  The push action is used to publish the changes made in a local branch to a remote branch of a Git repository. This action will update the remote branch with the commits made in the local branch and synchronize the two branches. The rebase action is used to reapply commits from one branch onto another branch, creating a linear history of commits. This action does not publish any changes to a remote repository. The tag action is used to create an annotated reference to a specific commit in a Git repository. This action does not publish any changes to a remote repository. The commit action is used to record changes made in the local repository and create a new snapshot of the project state. This action does not publish any changes to a remote repository.

  References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 20: Writing and Executing Bash Shell Scripts, page 579.

• Question 299:

  An administrator installed an application from source into /opt/operations1/ and has received numerous reports that users are not able to access the application without having to use the full path /opt/operations1/bin/*. Which of the following commands should be used to resolve this issue?

  A. echo 'export PATH=$PATH:/opt/operations1/bin' >> /etc/profile
  B. echo 'export PATH=/opt/operations1/bin' >> /etc/profile
  C. echo 'export PATH=$PATH/opt/operations1/bin' >> /etc/profile
  D. echo 'export $PATH:/opt/operations1/bin' >> /etc/profile
  A. echo 'export PATH=$PATH:/opt/operations1/bin' >> /etc/profile

  ---

  Explanation

  The command echo 'export PATH=$PATH:/opt/operations1/bin' >> /etc/profile should be used to resolve the issue of users not being able to access the application without using the full path. The echo command prints the given string to the standard output. The export command sets an environment variable and makes it available to all child processes. The PATH variable contains a list of directories where the shell looks for executable files. The $PATH expands to the current value of the PATH variable. The : separates the directories in the list. The /opt/operations1/bin is the directory where the application is installed. The >> operator appends the output to the end of the file. The /etc/profile file is a configuration file that is executed when a user logs in. The command echo 'export PATH=$PATH:/opt/operations1/bin' >> /etc/profile will add the /opt/operations1/bin directory to the PATH variable for all users and allow them to access the application without using the full path. This is the correct command to use to resolve the issue. The other options are incorrect because they either overwrite the PATH variable (echo 'export PATH=/opt/operations1/bin' >> /etc/profile) or do not use the correct syntax (echo 'export PATH=$PATH/opt/operations1/bin' >> /etc/profile or echo 'export $PATH:/opt/operations1/bin' >> /etc/profile).

  References: CompTIA Linux+ (XK0- 005) Certification Study Guide, Chapter 9: Working with the Linux Shell, page 295.

• Question 300:

  A Linux administrator is configuring a new internal web server fleet. The web servers are up and running but can only be reached by users directly via IP address. The administrator is attempting to fix this inconvenience by requesting appropriate records from the DNS team. The details are: Hostname: devel.comptia.org

  IP address: 5.5.5.1, 5.5.5.2, 5.5.5.3, 5.5.5.4

  Name server: 5.5.5.254

  Additional names: dev.comptia.org, development.comptia.org

  Which of the following types of DNS records should the Linux administrator request from the DNS team? (Select three).

  A. MX
  B. NS
  C. PTR
  D. A
  E. CNAME
  F. RRSIG
  G. SOA
  H. TXT
  I. SRV
  B. NS
  D. A
  E. CNAME

  ---

  Explanation

  The Linux administrator should request the following types of DNS records from the DNS team:

  A: This record type is used to map a hostname to an IPv4 address. The administrator needs four A records for devel.comptia.org, one for each IP address (5.5.5.1, 5.5.5.2, 5.5.5.3, 5.5.5.4). This will allow users to access the web servers by using the hostname devel.comptia.org instead of the IP addresses1. CNAME: This record type is used to create an alias for another hostname. The administrator needs two CNAME records, one for dev.comptia.org and one for development.comptia.org, both pointing to devel.comptia.org. This will allow users to access the web servers by using any of these three hostnames interchangeably1. NS: This record type is used to delegate a domain or a subdomain to another name server. The administrator needs one NS record for comptia.org, pointing to 5.5.5.254, which is the name server that hosts the records for the subdomain devel.comptia.org2. This will allow users to resolve the hostnames under comptia.org by querying the name server 5.5.5.2542. The other record types are not relevant for the administrator's task: MX: This record type is used to specify the mail exchange server for a domain or a subdomain1. The administrator does not need this record type because the web servers are not intended to handle email traffic. PTR: This record type is used to map an IP address to a hostname, which is the reverse of an A record1. The administrator does not need this record type because the web servers are not expected to be accessed by their IP addresses. RRSIG: This record type is used to provide digital signatures for DNSSEC, which is a security extension for DNS that verifies the authenticity and integrity of DNS responses3. The administrator does not need this record type because it is not mentioned in the task requirements. SOA: This record type is used to provide information about the authoritative name server and other parameters for a domain or a subdomain1. The administrator does not need this record type because it is usually created automatically by the name server software when a new zone file is created4. TXT: This record type is used to store arbitrary text data that can be used for various purposes, such as SPF, DKIM, DMARC, etc1. The administrator does not need this record type because it is not related to the web server functionality. SRV: This record type is used to specify the location and port number of a service that runs on a domain or a subdomain1. The administrator does not need this record type because the web servers use the standard HTTP port 80, which does not require an SRV record.

  References: 1: DNS Record Types ?CompTIA Network+ N10-007 ?1.8 2: NS Record - DNSimple Help 3: DNSSEC - Wikipedia 4: SOA Record - DNSimple Help