XK0-006 CompTIA Linux+ V8 Exam Question and Answers

Log management is a critical system management function highlighted in CompTIA Linux+ V8, particularly in multi-server environments. As the number of systems and applications grows, managing logs locally on each server becomes inefficient and error-prone.

The best solution is to implement a centralized log aggregation solution, making option B correct. Centralized logging collects logs from multiple systems and applications into a single, secure location. This simplifies monitoring, searching, correlation, auditing, and incident response. Common solutions include syslog servers, ELK/EFK stacks, and SIEM platforms.

Linux+ V8 documentation emphasizes centralized logging as a best practice for availability, troubleshooting, and security analysis. It enables administrators to detect patterns, investigate incidents, and maintain compliance more effectively than isolated log files.

The other options are insufficient on their own. On-demand retrieval does not scale well. Log backups protect data but do not simplify analysis. Log rotation manages disk usage but does not address distributed log complexity.

Therefore, the correct answer is B. Implement a centralized log aggregation solution.

To create an appropriate device label, format and create an ext4 file system on the new partition, you can use the following commands:

To create a GPT (GUID Partition Table) label on the new drive /dev/sdc, you can use the parted command with the -s option (for script mode), the device name (/dev/sdc), the mklabel command, and the label type (gpt). The command is:

parted -s /dev/sdc mklabel gpt

To create a primary partition of 10 GB on the new drive /dev/sdc, you can use the parted command with the -s option, the device name (/dev/sdc), the mkpart command, the partition type (primary), the file system type (ext4), and the start and end points of the partition (1 and 10G). The command is:

parted -s /dev/sdc mkpart primary ext4 1 10G

To format and create an ext4 file system on the new partition /dev/sdc1, you can use the mkfs command with the file system type (ext4) and the device name (/dev/sdc1). The command is:

mkfs.ext4 /dev/sdc1

You can verify that the new partition and file system have been created by using the lsblk command, which will list all block devices and their properties.

This issue is best analyzed using a layered troubleshooting approach, as recommended in the Troubleshooting domain of CompTIA Linux+ V8. The reported symptom is intermittent or random disconnections from an NFS share, which commonly indicates a network reliability issue rather than a configuration or filesystem problem.

The most critical evidence comes from the output of ip -s link show. The network interface enp1s0 is reporting significant numbers of errors and dropped packets on both the receive (RX) and transmit (TX) paths. High packet loss at the network interface level directly affects protocols like NFS, which rely on stable, continuous TCP/IP communication. When packets are dropped or corrupted, NFS clients may experience timeouts, retransmissions, and apparent disconnections.

Although the df -h output shows that the NFS filesystem is 95% full, this alone does not typically cause random disconnections. A nearly full filesystem may lead to write failures or performance degradation, but it does not explain intermittent connectivity loss. Linux+ V8 documentation notes that filesystem capacity issues usually present as I/O errors, not transport-layer disconnects.

Options A and B can also be ruled out. If the mount point or IP address were incorrect, the NFS share would fail consistently rather than intermittently. The fact that the share is mounted and accessible confirms that the mount configuration and IP addressing are correct.

Linux+ V8 emphasizes that NFS performance and reliability are highly sensitive to network quality. Packet errors, drops, faulty NICs, cabling issues, duplex mismatches, or driver problems commonly result in unstable NFS behavior.

Therefore, the best explanation for the reported random disconnections is D. The interface is reporting a high number of errors and dropped packets.

Filesystem unmount failures are common troubleshooting scenarios covered in Linux+ V8. When the error “target is busy” appears, it means one or more processes are actively using files or directories within the mount point.

The correct diagnostic command is lsof | grep /data1. The lsof (list open files) utility displays all open files and the processes using them. Filtering the output with grep /data1 identifies exactly which processes are holding file descriptors on the filesystem, preventing it from being unmounted.

The other options are incorrect. ps -f displays process information but does not show open file usage. du -sh calculates disk usage and does not identify active processes. top monitors system performance but cannot pinpoint filesystem locks.

Linux+ V8 documentation emphasizes using lsof or fuser to identify resource locks before unmounting filesystems. Therefore, the correct answer is D.

Ansible architecture and core components are part of the Automation, Orchestration, and Scripting domain in CompTIA Linux+ V8. Among these components, the inventory plays a foundational role in defining the infrastructure Ansible manages.

An Ansible inventory is a file (or set of files) that contains a list of managed hosts and optionally organizes them into logical groups. These hosts can be defined by IP address, fully qualified domain name (FQDN), or hostname. Inventories may be written in INI, YAML, or dynamically generated formats. Grouping hosts allows administrators to apply configurations, roles, and tasks to multiple systems simultaneously.

Option B, Inventory, is correct because it explicitly defines which systems Ansible will target. Without an inventory, Ansible does not know where to execute tasks. Linux+ V8 documentation emphasizes inventories as the starting point for all Ansible operations.

The other options are incorrect. Facts are system variables automatically collected by Ansible about managed hosts, such as OS version or IP address. Playbooks define what actions to perform but rely on the inventory to know where to perform them. Collections are distribution units that package roles, modules, and plugins, not host definitions.

Therefore, the correct answer is B. Inventory.

Comprehensive and Detailed 250 to 350 words of Explanation From Linux+ V8 documents:

Live migration is a virtualization feature that allows a running virtual machine to be moved from one host to another with minimal or no downtime. This topic falls under System Management in the CompTIA Linux+ V8 objectives, particularly in the areas of virtualization and resource management.

For a live migration to succeed, the CPU architecture must match between the source and destination hosts. This is critical because the running virtual machine’s CPU state, instruction set, and registers must be compatible with the destination system. Migrating between different CPU architectures (for example, x86_64 to ARM) is not supported and would cause the virtual machine to fail. Therefore, option D is required.

Additionally, the destination host must have sufficient available memory to accommodate the virtual machine being migrated. During live migration, the memory contents of the running VM are copied from the source host to the destination host while the VM continues to run. If enough memory is not available, the migration cannot complete successfully. This makes option E mandatory.

The other options are not strict requirements. USB ports do not need to match for live migration. Network speed may affect migration performance but does not need to be identical. Available swap space is not directly required for migration. Disk storage paths do not need to match as long as shared storage or compatible storage access is available.

Linux+ V8 documentation emphasizes CPU compatibility and memory availability as core prerequisites for live migration. Therefore, the correct answers are D and E.

Comprehensive and Detailed Explanation From Exact Extract:

To temporarily configure a Linux virtual machine as a router, the technician must enable IP forwarding and set up iptables rules to allow and masquerade traffic:

A. echo "1" > /proc/sys/net/ipv4/ip_forward: Enables IPv4 forwarding in the Linux kernel, allowing the VM to forward packets between interfaces.

B. iptables -A FORWARD -j ACCEPT: Adds a rule to the iptables firewall to accept all forwarded packets (allows traffic to be routed).

G. iptables -t nat -s 10.10.204.0/24 -A POSTROUTING -j MASQUERADE: Sets up network address translation (NAT) for outgoing packets from the 10.10.204.0/24 subnet, masquerading them as if they are coming from the VM’s external IP.

Other options:

C. and H. are not relevant for routing/NAT in this context (PREROUTING is generally used for DNAT, not for standard source NAT).

D. is syntactically incorrect and mixes PREROUTING with MASQUERADE, which is not the proper combination for SNAT.

E. disables forwarding.

F. is not related to IP forwarding.

Comprehensive and Detailed 250 to 350 words of Explanation From Linux+ V8 documents:

Passwordless authentication using SSH key pairs is a foundational security practice covered in the Security domain of CompTIA Linux+ V8. It allows administrators to securely authenticate between systems without transmitting passwords over the network, significantly reducing the risk of credential compromise.

The correct approach involves two essential steps: generating an SSH key pair and installing the public key on the remote system. Option A correctly performs both steps using best-practice commands.

The command ssh-keygen -t rsa generates an RSA public/private key pair in the user’s ~/.ssh/ directory. The private key (id_rsa) remains securely on the local system, while the public key (id_rsa.pub) is intended to be shared. The second part of the command, ssh-copy-id -i ~/.ssh/id_rsa.pub john@server2, securely copies the public key to the remote server’s ~/.ssh/authorized_keys file. This enables key-based authentication for the specified user.

The other options are incorrect or incomplete. Option B uses ssh-keyscan, which is intended for collecting host keys to populate known_hosts, not for user authentication. Option C misuses ssh-agent, which manages keys already generated and does not create or install them. Option D is insecure and incorrect because copying the entire .ssh directory risks exposing private keys and violates security best practices.

Linux+ V8 documentation emphasizes the use of ssh-keygen and ssh-copy-id as the standard, secure method for configuring passwordless SSH access. This approach ensures proper permissions, correct key placement, and minimal risk.

Comprehensive and Detailed Explanation From Exact Extract:

To add a new physical disk to LVM, the disk must first be initialized as a physical volume using the pvcreate command. This prepares the new disk for use by the LVM subsystem. After initializing with pvcreate, you would use vgextend to add the new physical volume to an existing volume group.

Other options:

A. vgextend adds a physical volume to a volume group, but you must use pvcreate first.

B. lvextend is used to increase the size of a logical volume, not to add a new disk.

D. pvresize is used to resize an existing physical volume, not to create one.

Comprehensive and Detailed Explanation From Exact Extract:

The ntpdate command synchronizes the system clock with a remote NTP server immediately, correcting any significant time drift. This is ideal for one-time corrections.

For example:

bash

CopyEdit

ntpdate pool.ntp.org

Other options:

A. hwclock reads or sets the hardware clock, but does not sync with network time.

C. timedatectl can set the time manually or manage time settings, but does not immediately sync with a remote NTP server.

D. ntpd -q can also sync the clock once, but ntpdate is designed specifically for immediate synchronization and is more straightforward for one-time corrections.

Comprehensive and Detailed Explanation From Exact Extract:

The chown command is used to change the owner and group of files and directories. The -R (recursive) flag ensures that all contents within the directory are also updated. The correct syntax is chown -R owner:group directory. So, chown -R Ansible:Ansible /opt/Ansible will change the owner and group for /opt/Ansible and everything inside it to "Ansible".

Other options:

A. groupmod is used to modify group properties, not ownership of directories or files.

C. usermod is for modifying user properties or group memberships.

D. chmod changes permissions, not owner/group.

Environment variables in Linux can exist either locally within a shell or be exported to child processes. CompTIA Linux+ V8 emphasizes the distinction between shell variables and environment variables, as this affects how applications inherit configuration values.

Option D, export ENABLE_AUTH=1, is the correct choice because it both assigns the variable and marks it for export to the environment. Once exported, the variable becomes available to all subsequently executed commands and child processes spawned from the current shell. This behavior is required when applications or scripts rely on environment variables for configuration.

Option B, ENABLE_AUTH=1, only sets a shell-local variable. While it is accessible within the current shell session, it is not inherited by child processes unless explicitly exported. Option A, let ENABLE_AUTH=1, performs arithmetic evaluation and does not export the variable. Option C incorrectly assigns the output of a command substitution and does not set the desired value.

Linux+ V8 documentation highlights export as the correct mechanism for making variables available system-wide within a user session. Therefore, the correct answer is D.

Comprehensive and Detailed Explanation From Exact Extract:

The lsscsi command is used to list information about SCSI devices (including storage arrays) that are attached to the system. This is critical when integrating a new storage array because it allows the administrator to verify that the operating system detects the new device at the SCSI layer, which is the underlying interface for most enterprise storage solutions. lsscsi outputs a list of recognized SCSI devices, their device nodes, and associated information.

Other options:

B. lsusb: Lists USB devices, not storage arrays on SCSI/SATA/SAS.

C. lsipc: Displays information on IPC (inter-process communication) facilities, unrelated to hardware detection.

D. lshw: Lists hardware details and can show storage, but lsscsi is specifically designed for SCSI device detection and is the most direct method for this task.

Version control rollback operations are a core DevOps skill covered in the Linux+ V8 objectives. When changes in a local Git repository break an application and must be reverted, the administrator must choose a command that directly undoes those changes.

The command git reset is the most appropriate option in this scenario. It allows the engineer to move the current branch pointer (HEAD) to a previous commit, effectively discarding or undoing local changes. Depending on the reset mode (--soft, --mixed, or --hard), the engineer can control whether changes are preserved in the staging area or working directory. This flexibility makes git reset the primary tool for reverting problematic local changes.

The other options are not suitable. git pull fetches and merges changes from a remote repository and does not revert local modifications. git rebase rewrites commit history and is used to reapply commits on top of another base, not to undo broken changes. git stash temporarily saves uncommitted changes for later use but does not revert the repository to a stable state.

Linux+ V8 documentation emphasizes that git reset is commonly used during local development when changes need to be undone quickly before being shared with others. Therefore, the correct answer is B.

File and directory management is a core system administration skill addressed in Linux+ V8. When an administrator needs to delete a directory that contains files or subdirectories, a recursive deletion is required.

The correct command is rm -r /home/user1/data. The rm command removes files, and the -r (recursive) option allows it to delete directories and all of their contents, including nested files and subdirectories. This is the standard and correct method for removing non-empty directories.

The other options are incorrect. rmdir -p only removes empty directories and will fail if the directory contains files. ln -d is used to create directory hard links, not remove directories. cut -d is a text-processing command unrelated to filesystem operations.

Linux+ V8 documentation stresses caution when using rm -r, as it permanently deletes data without recovery unless backups exist. Therefore, the correct answer is C.

User account information is centrally stored in the system’s account databases, and Linux+ V8 emphasizes the use of standard tools to query this data safely and consistently.

The getent passwd accounting command retrieves the user’s entry from the passwd database, which may be sourced from local files or network services such as LDAP. This entry includes the username, user ID (UID), group ID (GID), home directory, and assigned login shell. Therefore, option A provides all the requested information in a single command.

Option B, id accounting, displays the UID and group memberships but does not show the home directory or assigned shell. Option C is incorrect because /etc/shadow contains password hashes and expiration data, not shell or home directory information. Option D, who accounting, only shows login sessions and does not provide account configuration details.

Linux+ V8 documentation highlights getent passwd as the preferred method for retrieving comprehensive user account information because it works across different authentication backends.

Thus, the correct answer is A.

According to the output of getfacl app, user1 has only "rw" (read and write) permissions, but lacks "x" (execute). Without execute permission, user1 cannot run the file. To allow user1 to execute app, you must update the ACL to add execute permission (e.g., setfacl -m u:user1:rwx app). Modifying "others" permissions (option B) is not secure or necessary, adding user1 to the wheel group (option C) is unrelated, and moving the file (option D) does not resolve permission issues.

Archive Tab – Create the archive from Ann’s home directory

Correct Command:

tar -cvf /tmp/ann.tar -C /home/ ann

Extract Tab – Extract the archive into Joe’s home directory

Correct Command:

tar -xvf /tmp/ann.tar -C /home/ joe

This performance-based question tests file archiving and restoration using tar, a core System Management skill in the CompTIA Linux+ V8 objectives. The task requires preserving Ann’s files and placing them correctly into Joe’s home directory.

🔹 Archive Phase Explanation

The goal of the first step is to archive Ann’s entire home directory without embedding the full path (/home/ann) inside the archive. This is accomplished using the -C option.

Command breakdown:

tar → archive utility

-c → create an archive

-v → verbose output (optional but allowed)

-f /tmp/ann.tar → specifies the archive file

-C /home/ → changes directory before archiving

ann → archives the ann directory only

This results in a clean archive containing Ann’s files without absolute paths, which is best practice and explicitly covered in Linux+ V8 documentation.

🔹 Extract Phase Explanation

The second step extracts the archived files into Joe’s home directory.

Command breakdown:

-x → extract

-v → verbose

-f /tmp/ann.tar → specifies the archive

-C /home/joe → extracts files directly into Joe’s home directory

This ensures Joe receives Ann’s files correctly under /home/joe/ann or directly under /home/joe depending on post-extraction handling, which matches Linux+ expectations for administrative user transitions.

Virtualization management is part of Linux system administration and is included in Linux+ V8 objectives. KVM virtual machines commonly use disk image formats such as qcow2, raw, or vmdk. Converting between these formats is a routine administrative task.

The correct tool for disk image conversion is qemu-img. This utility allows administrators to create, convert, resize, and inspect virtual disk images. For example, converting a qcow2 image to raw format can be accomplished using qemu-img convert. This capability is explicitly referenced in Linux+ V8 documentation related to virtualization tooling.

The other options are incorrect. qemu-kvm refers to the hypervisor component, not disk manipulation. qemu-ng is not a valid QEMU utility. qemu-io is used for low-level I/O testing and debugging, not image format conversion.

Therefore, the correct answer is D. qemu-img.

This issue falls under the Troubleshooting domain of the CompTIA Linux+ V8 objectives, specifically service startup failures and certificate-related errors. The provided output clearly indicates that the NGINX service fails during startup due to an inability to locate the private key file.

The critical error message is:

cannot load certificate key "/etc/pki/nginx/private/server.key": No such file or directory

This message confirms that NGINX is explicitly configured to look for the private key in the directory /etc/pki/nginx/private/. However, the directory listing shows that the private directory exists but is empty, while the server.key file is located in /etc/pki/nginx/ instead. Because NGINX cannot find the private key at the configured path, the configuration test (nginx -t) fails, and systemd prevents the service from starting.

Option C correctly identifies the root cause: the private key is not in the correct location. Moving server.key into /etc/pki/nginx/private/ (or updating the NGINX configuration to match the current location) would resolve the issue. Linux+ V8 documentation stresses that service failures often result from misaligned configuration paths rather than corrupted files.

The other options are incorrect. Option A incorrectly refers to renaming a certificate file and does not address the path issue. Option B suggests a key mismatch, which would generate a different SSL error rather than a “file not found” error. Option D is also incorrect because private keys should not have executable permissions like 0755; typically, they are restricted (for example, 0600) for security reasons.

Therefore, the web service is not responding because the private key file is not located in the directory expected by the NGINX configuration. The correct answer is C.

This scenario falls under the Security domain of the CompTIA Linux+ V8 objectives and focuses on system hardening and service minimization. The Nmap scan output reveals that port 23 (Telnet) is open on the system, which represents a significant security risk.

Telnet is an insecure, legacy protocol that transmits authentication credentials and session data in plaintext, making it vulnerable to interception through packet sniffing or man-in-the-middle attacks. Linux+ V8 documentation explicitly emphasizes the principle of least functionality, which states that unnecessary or insecure services should be disabled and removed entirely rather than merely restricted.

Option D, disabling and removing the Telnet service on the server, is the best and most secure solution. This action eliminates the vulnerable service completely, ensuring that it cannot be exploited internally or externally. In secure Linux environments, Telnet should be replaced with SSH, which provides encrypted communication and strong authentication mechanisms.

Option A, blocking port 23 with a firewall, reduces exposure but does not eliminate the underlying risk. If the firewall rules are misconfigured or bypassed, the Telnet service would still be available. Linux+ V8 best practices recommend removing insecure services rather than relying solely on perimeter controls.

Option B is unrelated, as changing passwords does not address the risk of plaintext credential transmission. Option C is incorrect because closing ports at the network switch level is not an appropriate or scalable solution for host-level service hardening and does not address internal access risks.

Linux+ V8 documentation consistently highlights service auditing, port scanning, and removal of insecure protocols as essential system hardening steps. Therefore, the most effective and secure remediation is to disable and remove the Telnet service.

Comprehensive and Detailed Explanation From Exact Extract:

wc -l counts the number of lines of input provided to it, which is commonly used to count the number of files when used with ls -l (excluding the header line). For example, ls -l /opt/application/home/ | wc -l gives the total count of lines, which corresponds to the number of files and directories (including the total line at the top).

Other options:

A. less is a pager utility.

B. tail -f shows the end of a file in real time.

C. tr -c translates or deletes characters, not for counting lines.

Part 1 – Begin the recovery process

Answer:

vgcfgrestore vg01 -f /etc/lvm/archive/vg01_00001-810050352.vg

Part 2 – Continue the recovery process

Answer:

lvchange -ay /dev/vg01/lv01

Part 3 – Complete recovery and access data

Answer:

mount /dev/vg01/lv01 /important_data

This performance-based question tests LVM recovery, a critical System Management skill in CompTIA Linux+ V8. The scenario indicates that a logical volume was removed, but the underlying physical volume and volume group metadata still exist.

🔹 Part 1: Restoring Volume Group Metadata

The first screenshot shows that:

Physical volumes (pvdisplay, pvs) still exist

The logical volume is missing

/etc/lvm/archive/ contains archived VG metadata

Linux automatically stores backups of LVM metadata in /etc/lvm/archive whenever changes are made. The correct first step is to restore the volume group metadata using:

vgcfgrestore vg01 -f /etc/lvm/archive/vg01_00001-810050352.vg

This restores the logical volume definitions but does not activate them yet.

This is the only correct starting point in Linux+ V8 recovery workflows.

🔹 Part 2: Activating the Logical Volume

After metadata restoration:

The LV exists but is inactive

blkid shows the LV as TYPE="LVM2_member"

The logical volume must be activated before it can be mounted:

lvchange -ay /dev/vg01/lv01

This makes the LV available under /dev/vg01/lv01.

Linux+ explicitly requires LV activation after recovery.

🔹 Part 3: Accessing the Data

The final output shows:

The filesystem type is xfs

The logical volume is now visible

Since there is no indication of filesystem corruption, no repair is required.

The correct final step is to mount the filesystem:

mount /dev/vg01/lv01 /important_data

This restores full access to the underlying data.