CompTIA Linux+ (XK0-006) practice questions

Exam overview XK0-006

Domain coverage 5 domains

• System Management (23%)
• Services and User Management (20%)
• Security (18%)
• Automation, Orchestration, and Scripting (17%)
• Troubleshooting (22%)

Sample questions 12 of 120 shown

1. Q1 System Management

   A Linux administrator needs to ensure that a server consistently resolves the hostname 'db-primary' to the IP address 10.50.1.15, regardless of the DNS server's configuration. This change must be persistent and take precedence over any DNS lookups for that specific hostname. Which of the following actions will achieve this goal?

   1. Configure 'search db-primary' in /etc/resolv.conf.
   2. Use the command 'ip route add 10.50.1.15 via [gateway] dev eth0'.
   3. Add 'nameserver 10.50.1.15' to the top of /etc/resolv.conf.
   4. Create an entry '10.50.1.15 db-primary' in the /etc/hosts file.

   The /etc/hosts file provides static hostname-to-IP mapping that takes precedence over DNS lookups by default (as configured in /etc/nsswitch.conf with the 'hosts: files dns' order). Adding the entry '10.50.1.15 db-primary' ensures that any query for 'db-primary' resolves to 10.50.1.15 without consulting DNS. The search directive in resolv.conf affects how partial names are resolved, not specific hostname mappings. The ip route command sets routing paths, not name resolution. Adding a nameserver entry specifies which DNS server to query, but does not override DNS responses.
2. Q2 System Management

   To achieve a balance between read performance and single-disk failure tolerance for a database server's data volume, a systems engineer is configuring a software RAID array using four identical disks. Which RAID level is the MOST appropriate choice for this requirement?

   1. RAID 0
   2. RAID 6
   3. RAID 5
   4. RAID 1

   RAID 5 uses block-level striping with distributed parity, providing a good balance of read performance (striping allows parallel reads) and single-disk fault tolerance (parity can rebuild the failed disk). With 4 disks, RAID 5 provides (N-1) disks worth of usable capacity. RAID 0 offers no fault tolerance. RAID 6 provides double parity but requires more overhead. RAID 1 (mirroring) provides fault tolerance but at 50% capacity cost and without the read performance benefits of striping across multiple disks.
3. Q3 System Management

   An administrator has installed a new suite of tools in /usr/local/customapp/bin. To ensure these new tools are used instead of any existing system tools with the same names, what command should be run to temporarily alter the command search path for the current session?

   1. export PATH="$PATH:/usr/local/customapp/bin/"
   2. alias customapp='/usr/local/customapp/bin/customapp'
   3. export PATH="/usr/local/customapp/bin:$PATH"
   4. setenv PATH /usr/local/customapp/bin:$PATH

   The PATH variable is searched in order from left to right. By prepending /usr/local/customapp/bin to the existing PATH (export PATH="/usr/local/customapp/bin:$PATH"), the shell will find tools in that directory before searching the standard system paths. This ensures the custom tools take precedence over system tools with the same name. Option A appends the directory, which means system tools would still be found first. Option B only works for the named command. Option D uses csh/tcsh syntax, not bash syntax.
4. Q4 System Management

   To permanently change the static IPv4 address of a network connection named 'production' to 192.168.1.100/24 on a system managed by NetworkManager, which command is the most appropriate?

   1. netplan apply --address=192.168.1.100/24 --connection=production
   2. ifconfig production 192.168.1.100 netmask 255.255.255.0
   3. nmcli connection modify production ipv4.addresses 192.168.1.100/24
   4. ip addr add 192.168.1.100/24 dev production

   On systems managed by NetworkManager, the nmcli tool is the correct command-line interface for managing connections. nmcli connection modify production ipv4.addresses 192.168.1.100/24 changes the static IP address persistently in the connection profile (stored in /etc/NetworkManager/system-connections/). The ifconfig and ip addr commands make runtime changes only. Netplan applies network configuration on Ubuntu systems but uses a different syntax.
5. Q5 System Management

   Which command is used to display detailed information about block devices on a Linux system?

   1. lsblk
   2. mount
   3. df
   4. fdisk

   lsblk (list block devices) displays information about all available block devices (hard drives, SSDs, partitions) in a structured tree format showing device names, sizes, types, and mount points. The mount command shows currently mounted filesystems. df displays disk space usage of mounted filesystems. fdisk is a partition table manipulator with an interactive interface.
6. Q6 System Management

   A Linux administrator is provisioning a new KVM virtual machine named dev-web01 using a command-line utility. The VM requires 2 vCPUs, 2048 MB of RAM, and must be configured to boot from the network (PXE) first. Which of the following commands correctly creates this VM?

   1. virt-install --name dev-web01 --vcpus 2 --memory 2048 --disk size=10 --network bridge:br0 --pxe
   2. virt-builder --name dev-web01 --vcpus 2 --mem 2048 --boot pxe
   3. virsh create dev-web01 --vcpus 2 --ram 2048 --boot network
   4. qemu-system-x86_64 --name dev-web01 --smp 2 --m 2048 --boot n

   virt-install is the standard command-line tool for provisioning new KVM virtual machines. The --pxe flag configures the VM to PXE boot from the network during the first boot. virt-builder is used to build disk images, not create running VMs. virsh create requires an existing XML definition file. qemu-system-x86_64 is a low-level emulator, not the standard management tool.
7. Q7 System Management

   A Linux administrator needs to increase the virtual capacity of a qcow2 disk file located at /vms/db01.qcow2 by 50GB. Which command should be executed on the hypervisor to achieve this?

   1. virt-df -h db01 --add 50G
   2. lvextend -L +50G /vms/db01.qcow2
   3. qemu-img resize /vms/db01.qcow2 +50G
   4. virsh blockresize db01 /vms/db01.qcow2 +50G

   qemu-img resize is the correct tool to resize virtual disk images. The +50G syntax adds 50GB to the existing capacity. lvextend is for LVM logical volumes, not qcow2 files. virt-df is a disk usage reporting tool. While virsh blockresize exists, qemu-img resize is the standard tool for this operation on the disk image file directly.
8. Q8 System Management

   System users are randomly disconnecting from a server. The system administrator checks the following output:

   # ping 192.168.1.1
   --- 192.168.1.1 ping statistics ---
   100 packets transmitted, 4 received, 96% packet loss
   # ip -s link show
   RX: errors 400000
   TX: errors 150000
   # ip route
   default via 192.168.1.1 dev enp0s25 proto dhcp src 192.168.1.102 metric 600

   Which of the following actions should the administrator take to resolve the issue?

   1. Assign a correct gateway
   2. Replace the NIC
   3. Increase the TTL of the ping
   4. Increase the MTU size

   The output shows 96% packet loss and massive error counts on the network interface (RX: 400000 errors, TX: 150000 errors). These extremely high hardware-level error counts strongly indicate a faulty NIC, bad cable, or damaged switch port. The routing table already shows a valid default gateway, so the gateway is correctly assigned. TTL and MTU settings would not cause this level of RX/TX errors. Replacing the NIC is the most direct solution.
9. Q9 System Management

   Enabling btrfs filesystem support requires loading its kernel module. Which command ensures the module and all its dependencies are loaded correctly?

   1. lsmod | grep btrfs
   2. insmod btrfs.ko
   3. depmod -a btrfs
   4. modprobe btrfs

   modprobe btrfs is the correct command because it intelligently loads the specified module along with all its dependencies. Unlike insmod, which requires the full path and does not resolve dependencies, modprobe looks up modules in /lib/modules/$(uname -r)/ and handles dependency resolution automatically. lsmod only lists currently loaded modules. depmod generates dependency files but does not load modules.
10. Q10 System Management

    Which of the following filesystems contains non-persistent or volatile data?

    1. /boot
    2. /usr
    3. /proc
    4. /var

    The /proc filesystem is a virtual (pseudo) filesystem that exists only in memory and contains runtime kernel and process information. It is dynamically generated by the kernel and does not persist across reboots. /boot contains boot loader files and kernel images (persistent). /usr contains user binaries, libraries, and documentation (persistent). /var contains variable data like logs and databases (persistent storage, though contents change).
11. Q11 System Management

    Which command is used to determine the version of a kernel module?

    1. modprobe bluetooth
    2. lsmod bluetooth
    3. depmod bluetooth
    4. modinfo bluetooth

    modinfo displays metadata information about a kernel module, including its version, author, description, license, filename, and dependencies. The version information, if defined by the module developer, is shown in the output. modprobe loads or unloads modules. lsmod lists currently loaded modules. depmod builds module dependency information.
12. Q12 System Management

    An administrator needs to delete a directory /home/user1/data and all of its contents. Which command should the administrator use?

    1. rmdir -p /home/user1/data
    2. ln -d /home/user1/data
    3. rm -r /home/user1/data
    4. cut -d /home/user1/data

    The rm -r (recursive) command removes directories and their contents, including all nested files and subdirectories. rmdir -p only removes empty directories. ln -d creates hard links for directories (limited functionality). cut -d is a text processing tool that splits text by a delimiter.

Answer all 120 questions with instant feedback →

Reader reviews 179 ratings

• I was skeptical about paying for exam prep, but the XK0-006 bank saved me. Covered everything I needed.

  ★★★★★★ Nathan R.

• Really well-structured XK0-006 practice set. I like that you can attempt questions multiple times and it tracks your progress.

  ★★★★★★ Lucas W.

• I used this alongside video courses for XK0-006 prep. The questions helped solidify what I learned from the lectures.

  ★★★★★★ Aria N.

• The XK0-006 exam was brutal, but these practice questions prepared me for the worst. Came out with a solid pass.

  ★★★★★★ Carter H.

• Solid XK0-006 prep. No complaints. Questions are relevant and the platform works well on both desktop and phone.

  ★★★★★★ Scarlett W.

• Good bang for your buck on the XK0-006 practice exam. Unlimited attempts means you can really drill the material.

  ★★★★★★ Zoey L.

Frequently asked questions

More CompTIA exams