LPIC-1 Practice Test 23 — 15 Questions

Question 1

An administrator wants to allow user 'john' to run all commands as root without a password. Which sudoers entry accomplishes this?

Accepted Answer

john ALL=(ALL) NOPASSWD: ALL. The sudoers entry 'john ALL=(ALL) NOPASSWD: ALL' grants user 'john' permission to run any command as any user (including root) from any host, and the NOPASSWD tag overrides the default password requirement, allowing passwordless execution. This matches the requirement precisely.

Answer

john ALL=NOPASSWD: /bin/su

Answer

john ALL=(ALL) ALL

Answer

john ALL=(ALL) PASSWD: ALL

Question 2

A system administrator needs to install a new kernel on a Debian-based system. Which TWO commands can be used to achieve this? (Choose TWO.)

Accepted Answer

apt-get install linux-image-5.10.0-20-amd64. Option C is correct because apt-get install linux-image-5.10.0-20-amd64 uses APT to resolve dependencies and install the specified kernel package from the configured Debian repositories, which is the standard way to install a new kernel on a Debian-based system. Option E is correct because dpkg -i linux-image-5.10.0-20-amd64.deb installs a locally downloaded kernel .deb package directly, which is a valid method when the package file is already present on the system. Option A is incorrect because apt-cache search only queries the package cache for available packages and does not install anything. Option B is incorrect because apt-get update merely refreshes the package index metadata from repositories and does not install a kernel. Option D is incorrect because make install is used to install software compiled from source, not to install a prebuilt Debian kernel package.

Answer

apt-cache search linux-image-5.10.0-20-amd64

Answer

apt-get update

Answer

make install

Question 3

Which TWO commands can be used to display the current runlevel of a system?

Accepted Answer

runlevel. The `runlevel` command (option D) reads `/var/run/utmp` and prints the previous and current runlevel (e.g., "N 5"), directly reporting the system's current runlevel. The `who -r` command (option E) uses the `-r` flag to display the current runlevel along with the time it was last changed, also deriving this from the utmp record. Option A, `telinit q`, only tells init to re-read its configuration and does not display the runlevel. Option B, `systemctl get-default`, shows the default target (e.g., graphical.target) that the system boots into, not the currently active runlevel. Option C, `init 3`, is used to change the runlevel to 3, not to display the current one.

Answer

telinit q

Answer

systemctl get-default

Answer

init 3

Question 4

Which THREE of the following commands can be used to display information about block devices?

Accepted Answer

lsblk. lsblk (A) is correct because it reads /sys/block and udev data to list all block devices in a tree, showing names, sizes, types, mountpoints, and major:minor numbers. fdisk -l (C) is correct because it enumerates the partition tables of all detected block devices, printing disk geometry, sector sizes, and partition layouts. blkid (D) is correct because it queries block-device attributes such as UUID, LABEL, and filesystem TYPE from the blkid cache and device superblocks. free (B) is not a block-device tool; it reports RAM and swap usage from /proc/meminfo. ip link (E) is a networking command that lists and manages network interfaces at layer 2, not block devices.

Answer

free

Answer

ip link

Question 5

Which TWO commands can be used to view the contents of a compressed file named archive.tar.gz without extracting it to disk?

Accepted Answer

tar -tzf archive.tar.gz. Option C, `tar -tzf archive.tar.gz`, is correct because the `-t` flag lists the archive contents, `-z` tells tar to filter through gzip, and `-f` specifies the archive file, so it lists the members of the gzipped tarball without writing them to disk. Option E, `zcat archive.tar.gz | tar -t`, is correct because `zcat` decompresses the gzip stream to standard output and pipes it into `tar -t`, which lists the archive contents from stdin without extracting files to disk. Option A, `gzip -d archive.tar.gz`, is wrong because `-d` decompresses the file, replacing it with `archive.tar` on disk rather than merely viewing contents. Option B, `bunzip2 -c archive.tar.gz | tar -t`, is wrong because `bunzip2` handles bzip2 compression, not gzip, so it cannot decompress a `.tar.gz` file. Option D, `gunzip -l archive.tar.gz`, is wrong because `gunzip -l` lists compression statistics for the gzip file itself, not the contents of the tar archive inside it.

Answer

gzip -d archive.tar.gz

Answer

bunzip2 -c archive.tar.gz | tar -t

Answer

gunzip -l archive.tar.gz

Question 6

Which TWO of the following are valid methods to change the default runlevel on a SysV init-based system?

Accepted Answer

Edit /etc/inittab to set the initdefault line.. Option B is correct because on a SysV init-based system the default runlevel is defined in /etc/inittab by the initdefault entry (e.g., id:3:initdefault:), which init reads at startup to determine which runlevel to enter. Option C is correct because passing a runlevel as a kernel boot parameter (e.g., appending '3' or 'single' to the kernel command line) overrides the initdefault setting for that boot, causing init to start in the specified runlevel. Option A is incorrect because the 'runlevel' command only reports the previous and current runlevels; it does not set them. Option D is incorrect because 'systemctl set-default' is a systemd command for setting the default target, not applicable to SysV init systems. Option E is incorrect because 'telinit' changes the runlevel of the currently running system immediately, but does not persistently alter the default runlevel configured in /etc/inittab.

Answer

Use the 'runlevel' command to set the default runlevel.

Answer

Use 'systemctl set-default' to set the default runlevel.

Answer

Use the 'telinit' command to change the default runlevel.

Question 7

After a failed package upgrade, a Debian system shows 'unmet dependencies' when trying to install any new software. What is the most appropriate command to fix this condition?

Accepted Answer

apt-get install -f. The 'apt-get install -f' command (option B) is the correct fix because it invokes the '--fix-broken' option, which automatically resolves unmet dependencies by either installing missing packages or removing partially installed ones. This is the standard Debian/APT tool for repairing a broken package state after a failed upgrade, as it reads the dpkg database and corrects inconsistencies without manual intervention.

Answer

Edit /var/lib/dpkg/status manually

Answer

dpkg --purge $(dpkg -l | grep ^iU | awk '{print $2}')

Answer

dpkg --force-depends -i *.deb

Question 8

Refer to the exhibit. How many physical disks are present in the system?

Accepted Answer

2. The output shows two SCSI disks: /dev/sda and /dev/sdb. Each device file represents a physical disk, so there are exactly two physical disks present. The partitions (sda1, sda2, sdb1) are subdivisions of those disks and do not count as separate physical disks.

Answer

3

Answer

4

Answer

1

Question 9

Which TWO characteristics describe the difference between 'apt-get' and 'aptitude'? (Choose two.)

Accepted Answer

Aptitude offers a text-based interactive interface (TUI).. Aptitude includes a text-based interactive interface (TUI) that allows users to browse, search, and manage packages in a menu-driven environment, whereas apt-get is strictly command-line only. This TUI provides features like visual dependency trees and interactive conflict resolution, making aptitude more user-friendly for interactive package management.

Answer

Apt-get uses a different package format than aptitude.

Answer

Apt-get can only be used from the command line, while aptitude only has a text-based interface.

Answer

Aptitude is an older tool and no longer maintained.

Question 10

A user submitted a print job to a CUPS printer but used the wrong options. Which command should the administrator use to cancel the job?

Accepted Answer

cancel. The `cancel` command is the correct CUPS utility to terminate a print job that has already been submitted. It accepts either a job ID (e.g., `cancel 123`) or a printer name (e.g., `cancel printer-name`) to cancel the currently active job on that printer. This command directly communicates with the CUPS daemon to remove the job from the queue.

Answer

lpstat

Answer

lprm

Answer

lpadmin

Question 11

A sysadmin notices that after modifying iptables rules, the SSH service is unreachable from a specific subnet (192.168.1.0/24). Which command should be used to view the current rules with line numbers for easier identification?

Accepted Answer

iptables -L --line-numbers. The `iptables -L --line-numbers` command displays all current iptables rules in the default filter table with line numbers prepended to each rule. This allows the sysadmin to easily identify and reference specific rules (e.g., for deletion or insertion) when troubleshooting why SSH traffic from 192.168.1.0/24 is being dropped or rejected.

Answer

iptables -L

Answer

iptables -t raw -L

Answer

iptables -t nat -L

Question 12

To add a kernel parameter temporarily to the kernel command line at boot, what key should be pressed in the GRUB menu?

Accepted Answer

e. Pressing 'e' in the GRUB menu enters the edit mode for the selected boot entry, allowing you to temporarily modify kernel parameters on the command line (e.g., adding 'single' for single-user mode or 'nomodeset' for graphics issues). These changes apply only to the current boot and are not saved to the GRUB configuration file.

Answer

b

Answer

r

Answer

c

Question 13

Based on the exhibit, the 'custom' repository shows 0 packages. What is the most likely cause?

Accepted Answer

The $releasever or $basearch variables are not expanding correctly, leading to an invalid URL. The 'custom' repository shows 0 packages because the $releasever or $basearch variables are not expanding correctly, resulting in an invalid or unreachable repository URL. Yum uses these variables to dynamically construct the baseurl, and if they are undefined or incorrect (e.g., due to a missing or misconfigured /etc/yum/vars/ directory or incorrect release version), the repository metadata cannot be downloaded, so yum reports 0 packages available.

Answer

The repository is disabled because 'enabled=1' is missing

Answer

The GPG key is missing, causing yum to ignore the repository

Answer

The repository metadata is corrupt and needs to be regenerated

Question 14

A system administrator wants to monitor network traffic on a specific port (TCP/443) entering the server. Which command will capture packets on interface eth0 and display them in real-time?

Accepted Answer

tcpdump -i eth0 port 443. C is correct because `tcpdump -i eth0 port 443` captures packets on interface eth0 filtering for TCP port 443 (HTTPS) and displays them in real-time as they arrive. This command uses the libpcap library to intercept raw network frames, making it the standard tool for live packet capture and analysis.

Answer

netstat -tulpn | grep :443

Answer

ss -tulpn | grep :443

Answer

iptables -L -n -v

Question 15

A user reports that when they run 'ls -l' in their home directory, they see files but all files have permissions like '-rwxrwxrwx', which is unexpected. The system administrator checks and finds that the user's umask is set to 000. The user wants all new files to be created with default permissions of -rw-r--r-- (644) and directories that are drwxr-xr-x (755). What should the user set their umask to?

Accepted Answer

022. The umask is a three-digit octal value that is subtracted from the default base permissions (666 for files, 777 for directories) to determine the default permissions for newly created files and directories. To achieve file permissions of 644 (rw-r--r--) and directory permissions of 755 (rwxr-xr-x), the umask must be 022. This is because 666 - 022 = 644 for files, and 777 - 022 = 755 for directories.

Answer

007

Answer

002

Answer

027