LPIC-2 Practice Test 28 — 15 Questions

Question 1

A system administrator compiled a custom kernel module for a new hardware device. After copying the .ko file to /lib/modules/$(uname -r)/, the module is not loading automatically at boot. What is the most likely cause?

Accepted Answer

The module is blacklisted in /etc/modprobe.d/.. Option D is correct because a blacklist entry in /etc/modprobe.d/ explicitly prevents the kernel from loading the module at boot, regardless of its presence in /lib/modules/$(uname -r)/. The modprobe system reads these configuration files during early boot and skips any module listed with a 'blacklist' directive, which is the most likely cause when a module is present but fails to load automatically.

Answer

The module needs to be added to /etc/modules.

Answer

The module has a dependency error.

Answer

The kernel version does not match the module.

Question 2

An administrator is setting up a Samba share for a project team. The team members are in different UNIX groups. Which three options can be used to restrict access to specific users or groups? (Choose three.)

Accepted Answer

read list. Option A (read list) is correct because it explicitly restricts read-only access to a list of users or groups, allowing the administrator to control which users can only read files in the Samba share. This is a direct Samba parameter that limits access to specific users or groups, even if they are in different UNIX groups.

Answer

write list

Answer

force group

Question 3

A Samba administrator needs to configure a share that allows only the user 'alice' and the group 'developers' to read and write files. Others should have no access. Which two parameters should be set in the share definition? (Choose two.)

Accepted Answer

valid users = alice, @developers. The 'valid users' parameter restricts access to only the specified users and groups, so setting 'valid users = alice, @developers' ensures only alice and members of the developers group can connect to the share. The 'write list' parameter grants write access to the listed users and groups, overriding any read-only setting; combining it with 'valid users' ensures that alice and the developers group have both read and write permissions, while all others are denied access entirely.

Answer

invalid users = alice, @developers

Answer

force user = alice

Answer

read list = alice, @developers

Question 4

A Samba share uses the 'acl_xattr' VFS module to store NT ACLs in extended attributes. The administrator runs 'getfattr -d /srv/share/file.txt' and sees no system attributes related to NT ACLs. What is the most likely cause?

Accepted Answer

The filesystem is not mounted with the 'user_xattr' option.. The 'acl_xattr' VFS module stores NT ACLs in extended attributes within the 'system' namespace. If 'getfattr -d' shows no system attributes, the most likely cause is that the underlying filesystem is not mounted with the 'user_xattr' option, which is required to enable extended attribute support. Without this mount option, the filesystem cannot store or retrieve extended attributes, so the NT ACL data is not persisted.

Answer

The VFS module is not loaded globally.

Answer

The share does not have 'nt acl support = yes' set.

Answer

The file's extended attributes are stored in a different namespace.

Question 5

An administrator needs to disable IPv6 on a running system without rebooting and make the change permanent across reboots. Which set of commands should be used?

Accepted Answer

echo 1 > /proc/sys/net/ipv6/conf/all/disable_ipv6 && edit /etc/sysctl.conf to add net.ipv6.conf.all.disable_ipv6=1. Option B is correct because it combines a runtime sysctl command to immediately disable IPv6 on the running system without a reboot, and a persistent configuration in /etc/sysctl.conf to ensure the setting survives reboots. The /proc/sys/net/ipv6/conf/all/disable_ipv6 file controls the IPv6 stack at runtime, and sysctl.conf applies the kernel parameter at boot time.

Answer

modprobe -r ipv6

Answer

Edit /boot/grub/grub.cfg to add ipv6.disable=1

Answer

sysctl -w net.ipv6.conf.all.disable_ipv6=1

Question 6

Which three directories or files are typically associated with the Linux kernel? (Choose three.)

Accepted Answer

/proc. /proc is a virtual filesystem that provides an interface to kernel data structures, exposing process information, system hardware details, and runtime kernel parameters. It is dynamically generated by the kernel and does not occupy disk space, making it a direct representation of kernel state.

Answer

/dev

Answer

/etc

Question 7

Which three steps are required to build a kernel module from source located outside the kernel tree? (Choose three.)

Accepted Answer

Run 'make modules_install'.. Option A is correct because 'make modules_install' copies the compiled kernel module (.ko file) to the appropriate directory under /lib/modules/$(uname -r)/, making it available for loading. This step is essential after building a module from external source to ensure it is installed in the correct location for the running kernel.

Answer

Edit the kernel configuration.

Answer

Use the kernel's top-level Makefile.

Question 8

Which two utilities can be used to load kernel modules? (Choose two.)

Accepted Answer

modprobe. modprobe is correct because it is the primary utility for loading kernel modules, including handling module dependencies automatically by consulting the modules.dep file generated by depmod. insmod is also correct because it directly inserts a single module into the kernel, though it does not resolve dependencies automatically.

Answer

modinfo

Answer

lsmod

Answer

depmod

Question 9

A system administrator notices that the 'pcspkr' kernel module is causing beeps on the server console. The administrator wants to prevent this module from loading permanently. Which of the following is the correct method to blacklist the module?

Accepted Answer

Add 'blacklist pcspkr' to /etc/modprobe.d/blacklist.conf. Option C is correct because the standard method to permanently prevent a kernel module from loading is to add a 'blacklist' directive to a file in /etc/modprobe.d/. The 'blacklist pcspkr' line tells modprobe not to load the pcspkr module automatically, even if it is requested by hardware detection or dependencies. This is the recommended approach on modern Linux distributions using modprobe's configuration system.

Answer

Add 'install pcspkr /bin/false' to /etc/modprobe.conf

Answer

Set the kernel parameter 'pcspkr=off' in GRUB

Answer

Remove the module file from /lib/modules/$(uname -r)/kernel/drivers/input/misc/

Question 10

A system administrator needs to include a custom kernel module in the initramfs to support a root filesystem on a USB device. Which command should be used to rebuild the initramfs with the updated kernel?

Accepted Answer

dracut. Dracut is the correct tool for rebuilding the initramfs on modern Red Hat-based distributions (e.g., RHEL, CentOS, Fedora). It automatically detects and includes kernel modules required for the root filesystem, including those for USB storage devices, and regenerates the initramfs image with the updated kernel module.

Answer

update-initramfs

Answer

mkinitrd

Answer

grub-mkconfig

Question 11

An administrator wants to disable the graphical splash screen during boot. What change should be made in /etc/default/grub?

Accepted Answer

Remove 'splash' from GRUB_CMDLINE_LINUX_DEFAULT. Option D is correct because the graphical splash screen during boot is controlled by the 'splash' kernel parameter. Removing 'splash' from GRUB_CMDLINE_LINUX_DEFAULT in /etc/default/grub disables the splash screen, allowing verbose boot messages to be displayed. This parameter is passed to the kernel via the bootloader, and its absence prevents the plymouth or similar splash service from activating.

Answer

Set GRUB_CMDLINE_LINUX="nosplash"

Answer

Remove 'quiet' from GRUB_CMDLINE_LINUX_DEFAULT

Answer

Set GRUB_TIMEOUT=0

Question 12

Which file is used by GRUB2 to load the kernel and initramfs?

Accepted Answer

/boot/grub/grub.cfg. GRUB2 uses /boot/grub/grub.cfg as its main configuration file, which contains the menu entries, kernel paths, and initramfs locations. This file is generated by update-grub (or grub-mkconfig) based on scripts in /etc/grub.d/ and settings in /etc/default/grub, and it is read directly by the GRUB2 bootloader at boot time to load the kernel and initramfs.

Answer

/etc/lilo.conf

Answer

/etc/default/grub

Answer

/boot/grub/menu.lst

Question 13

During boot, the kernel panics because the root filesystem cannot be mounted. Which kernel parameter should be added at the GRUB prompt to try an alternative root device?

Accepted Answer

root=/dev/sdb1. The kernel parameter 'root=' specifies the device for the root filesystem. When the default root device fails to mount, adding 'root=/dev/sdb1' at the GRUB prompt overrides the compiled-in root and tells the kernel to attempt mounting from that alternative block device. This is the standard method to redirect the root mount during boot troubleshooting.

Answer

init=/bin/sh

Answer

rescue

Answer

single

Question 14

An administrator wants to compile a new kernel module that is not yet in the tree. What file should be referenced to ensure the module is built with the same configuration as the current kernel?

Accepted Answer

/boot/config-5.10.0-9-amd64. Option B is correct because /boot/config-5.10.0-9-amd64 contains the exact kernel configuration used to build the currently running kernel. When compiling a new kernel module, referencing this file (typically via 'make oldconfig' or copying it to the source tree as .config) ensures the module is built with the same set of options, such as enabled features, drivers, and module parameters, preventing incompatibilities.

Answer

/proc/config.gz

Answer

/boot/System.map-5.10.0-9-amd64

Answer

/boot/initrd.img-5.10.0-9-amd64

Question 15

After upgrading the kernel on a Red Hat Enterprise Linux system, the system fails to boot because the initramfs is missing. Which command can be used to regenerate the initramfs?

Accepted Answer

dracut -f. On Red Hat Enterprise Linux (RHEL) systems, the `dracut` utility is the standard tool for creating and regenerating initial RAM filesystem images (initramfs). The `-f` (force) option overwrites an existing initramfs file, which is necessary after a kernel upgrade to ensure the new kernel has the correct drivers and modules to mount the root filesystem during boot. Without a valid initramfs, the kernel cannot access the root filesystem, causing a boot failure.

Answer

mkinitrd -f

Answer

grub2-mkconfig -o /boot/grub2/grub.cfg

Answer

mkinitramfs -o /boot/initrd.img