XK0-005 Exam Dumps - CompTIA Linux+ Exam

The server’s CPU is spending too much time waiting for data inputs. This can be inferred from the output of the top command, which shows the percentage of CPU time spent in different states. The wa state stands for wait, and it indicates that the CPU is idle while waiting for an I/O operation to complete. In this case, the wa state is 52.4%, which means that more than half of the CPU time is wasted on waiting for data inputs. This can cause a high I/O latency and affect the performance of the server.

The other options are not correct based on the output received from the executed command. The server’s CPU is not taking too long to process users’ requests, because the us state, which stands for user, is only 0.2%, which means that the CPU is barely used by user processes. The server’s CPU does not show a high idle-time value, because the id state, which stands for idle, is 0.0%, which means that the CPU is not idle at all. The server’s CPU value for the time spent on system processes is not low, because the sy state, which stands for system, is 33.1%, which means that the CPU is heavily used by system processes.

References: How to Use the Linux top Command (and Understand Its Output); [Understanding Linux CPU Load - when should you be worried?]

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.

The firewall-cmd --zone=public --permanent --add-service=ssh command will resolve the issue by allowing SSH connections on port 22 in the public zone of the firewalld service. This command will add the ssh service to the permanent configuration of the public zone, which means it will persist after a reboot or a reload of the firewalld service. The firewall-cmd --zone=public --permanent --add-service=22 command is invalid, as 22 is not a valid service name. The systemct1 enable firewalld; systemct1 restart firewalld command will enable and restart the firewalld service, but it will not change the firewall rules. The firewall-cmd --zone=public --permanent --add-port=22/udp command will allow UDP traffic on port 22 in the public zone, but SSH uses TCP, not UDP. References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 18: Securing Linux Systems, page 543.

To ensure all files created in Q1 inherit the group ownership of finance, the chmod g+s command sets the group ID (SGID) on the directory, ensuring new files belong to the group of the directory. chown Finance Q1/ changes the group ownership of Q1 to Finance, allowing Finance group members access. These settings facilitate collaborative permissions as per CompTIA Linux+ recommendations for group-based file sharing. Reference: CompTIA Linux+ Study Guide.

The issue is that the administrator did not set the default target to graphical.target. A target is a unit of systemd that groups together other units by a common purpose or state. The graphical.target is a target that starts the graphical user interface (GUI) along with other services. The administrator used the command systemct1 isolate graphical.target to switch to this target temporarily, but this does not change the default target that is activated at boot time. To make this change permanent, the administrator should have used the command systemct1 set-default graphical.target, which creates a symbolic link from /etc/systemd/system/default.target to /usr/lib/systemd/system/graphical.target.

The other options are not correct explanations for the issue. The administrator did reboot the server properly by using systemct1 reboot, which shuts down and restarts the system cleanly. The administrator did not need to set the default target to basic.target, which is a minimal target that only starts essential services. The administrator did not shut down the server improperly, which could have caused file system corruption or data loss, but not affect the default target. References: systemct1(1) - Linux manual page; How to Change Runlevels (targets) in SystemD

To enable LUKS on a USB storage device with an ext4 filesystem format, the administrator needs to perform the following steps:

Unmount the device if it is mounted using umount /dev/sdc (D)

Create a partition table on the device using fdisk /dev/sdc (E)

Format the partition with LUKS encryption using cryptsetup luksFormat /dev/sdc1 (H)

Open the encrypted partition using cryptsetup luksOpen /dev/sdc1 LUKS0001

Create an ext4 filesystem on the encrypted partition using mkfs.ext4 /dev/mapper/LUKS0001 ©

Mount the encrypted partition using mount /dev/mapper/LUKS0001 /mnt References:

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

[How to Encrypt USB Drive on Ubuntu 18.04]

The file /etc/ssh/sshd_config contains the configuration settings for the SSH daemon, which handles the secure remote login. To change the port number, the engineer should edit this file and modify the line that says Port 22 to Port 49000. The other files are not related to the SSH service. References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 13: Managing Network Services, page 411.

The best commands to use to generate a list of rogue process names that have a TCP listener on a network interface are A. netstat -antp | grep LISTEN and B. lsof -iTCP | grep LISTEN. These commands will show the process ID (PID) and name of the processes that are listening on TCP ports, which can be used to identify any suspicious or unauthorized processes. The other commands are either not specific enough, not valid, or not relevant for this task. For example:

C. lsof -i:22 | grep TCP will only show the processes that are listening on port 22, which is typically used for SSH, and not any other ports.

D. netstat -a | grep TCP will show all the TCP connections, both active and listening, but not the process names or IDs.

E. nmap -p1-65535 | grep -i tcp will scan all the TCP ports on the local host, but not show the process names or IDs.

F. nmap -sS 0.0.0.0/0 will perform a stealth scan on the entire internet, which is not only impractical, but also illegal in some countries.