50 Free LPIC-1 Practice Questions (with Answers & Explanations)

Answer: b) dmesg

Explanation: dmesg displays the kernel ring buffer, which contains boot messages, hardware detection info, and kernel-level events. While journalctl --kernel (systemd systems) can also show kernel messages, dmesg is the traditional and most direct command specified in the LPIC-1 objectives.

Answer: a) /proc/modules

Explanation: /proc/modules shows all kernel modules currently loaded. The lsmod command reads this file and formats its output. While lsmod is more readable, the LPIC-1 exam sometimes asks about the underlying file.

Answer: b) modprobe

Explanation: modprobe loads a kernel module and automatically resolves and loads all dependencies. insmod loads a single module without dependency resolution. depmod generates the dependency database that modprobe uses.

Answer: a) IRQ 0

Explanation: IRQ 0 is reserved for the system timer (PIT — Programmable Interval Timer). IRQ 1 is for the keyboard, IRQ 8 is for the real-time clock, and IRQ 14 is for primary IDE/PATA.

Answer: a) lspci -v

Explanation: lspci -v displays PCI device information in verbose format. lspci -vv or -vvv provides even more detail but -v is the standard verbose flag specified in the LPIC-1 objectives.

Answer: c) /sys/

Explanation: /sys/ (sysfs) provides device and driver information in a hierarchical tree structure. /proc/ contains process and system information in a flat layout. /dev/ contains device files, not driver information.

Answer: b) lsusb -t

Explanation: lsusb -t shows USB devices in a tree format, displaying the USB bus hierarchy. lsusb without options shows a flat list.

Answer: a) /proc/ioports

Explanation: /proc/ioports lists I/O port address ranges assigned to devices. Other /proc/ files relevant to hardware include /proc/interrupts (IRQs), /proc/dma (DMA channels), and /proc/cpuinfo (CPU info).

Answer: c) Any .conf file in /etc/modprobe.d/ with blacklist keyword

Explanation: You can create any .conf file in /etc/modprobe.d/ and add blacklist module_name to prevent a module from loading. The file name is arbitrary (e.g., /etc/modprobe.d/disable-beep.conf).

Answer: b) EFI System Partition (ESP)

Explanation: UEFI systems boot from the EFI System Partition (ESP), typically formatted as FAT32 and mounted at /boot/efi/ or /efi/. The ESP contains .efi boot loader files. Legacy BIOS systems use the MBR.

Answer: d) Both a) and c)

Explanation: Both dpkg -i and dpkg --install install a local .deb package. apt install can also install local packages, but dpkg -i and dpkg --install are the direct commands specified in LPIC-1 objectives.

Answer: c) rpm -Va

Explanation: rpm -Va verifies all installed packages by comparing file attributes against the RPM database. rpm -V or rpm --verify verifies specific packages (when named), not all packages. The a flag is needed to verify all packages.

Answer: a) /etc/apt/sources.list and files in /etc/apt/sources.list.d/

Explanation: APT reads repository definitions from /etc/apt/sources.list and additional .list files in /etc/apt/sources.list.d/. This modular approach allows software vendors to provide their own repository files.

Answer: b) Upgrades all installed packages to their latest versions

Explanation: yum update (or yum upgrade) upgrades all installed packages to the latest available versions. yum makecache or yum check-update refreshes the package metadata.

Answer: a) rpm -qf /etc/hosts

Explanation: rpm -qf (query file) determines which installed package owns a specified file. rpm -ql lists files in a package, rpm -qi shows package info, and rpm -qs shows file states.

Answer: d) Both b) and c)

Explanation: ldconfig creates, updates, and removes the shared library cache (/etc/ld.so.cache) used by the dynamic linker. It also configures the run-time bindings by scanning trusted directories and /etc/ld.so.conf.

Answer: b) apt purge package

Explanation: apt purge (or dpkg -P) removes a package and its configuration files. apt remove (or dpkg -r) removes the package but leaves configuration files behind. apt autoremove removes packages installed as dependencies that are no longer needed.

Answer: a) /etc/yum.repos.d/*.repo

Explanation: YUM and DNF repositories are defined in .repo files under /etc/yum.repos.d/. Each file can define one or more repositories. The main configuration file is /etc/yum.conf.

Answer: b) Lists directories to search for shared libraries

Explanation: /etc/ld.so.conf lists directories where the dynamic linker searches for shared libraries. It typically includes /etc/ld.so.conf.d/*.conf for modular configuration. The ldconfig command reads these files and builds /etc/ld.so.cache.

Answer: d) Both a) and b)

Explanation: Both dpkg -l and dpkg --list list all installed packages. dpkg -L lists files installed by a specific package (different function).

Answer: a) Counts lines containing "error" (case-sensitive)

Explanation: grep -c counts the number of lines that match the pattern (not the total number of matches — multiple matches on the same line count as 1). Use grep -o to count total matches.

Answer: a) find / -mtime +7

Explanation: -mtime +7 finds files modified more than 7 days ago. -mtime -7 finds files modified within the last 7 days. -mtime 7 finds files modified exactly 7 days ago. -ctime is for status changes, -atime is for access time.

Answer: a) > overwrites, >> appends

Explanation: > redirects output to a file, overwriting its contents. >> redirects output to a file, appending to the end. Both redirect stdout by default.

Answer: a) cat

Explanation: cat (concatenate) reads files sequentially and writes them to stdout. paste merges files line by line (side by side). join joins lines based on a common field.

Answer: a) Sets permissions to rwxr-x---

Explanation: 7 (owner) = rwx (4+2+1), 5 (group) = r-x (4+0+1), 0 (others) = --- (0+0+0). The resulting permissions are owner: read, write, execute; group: read, execute; others: no access.

Answer: b) sed 's/foo/bar/g' file.txt

Explanation: The g (global) flag replaces all occurrences on each line. Without g, only the first match per line is replaced. The y command does character transliteration (not string replacement).

Answer: b) Reads from stdin and writes to both stdout and files

Explanation: tee reads from standard input and writes to both standard output and one or more files. Example: echo "hello" | tee file.txt displays "hello" on the terminal and writes it to file.txt.

Answer: a) cut -d ':' -f 2

Explanation: -d specifies the delimiter (field separator) and -f selects the field(s). -c selects character positions, and -b selects byte positions.

Answer: b) Converts stdin to command-line arguments

Explanation: xargs reads items from standard input (separated by blanks or newlines) and executes a command with those items as arguments. Example: find /tmp -name "*.tmp" | xargs rm.

Answer: d) All of the above

Explanation: All three command variants display all processes: ps aux (BSD syntax), ps -ef (standard syntax), and ps -A (all processes). LPIC-1 expects familiarity with both BSD and standard syntax.

Answer: b) SIGKILL (9)

Explanation: kill -9 sends SIGKILL, which immediately terminates the process without allowing cleanup. SIGTERM (15) is the default and asks processes to terminate gracefully. SIGHUP (1) reloads configuration, and SIGINT (2) is triggered by Ctrl+C.

Answer: b) du -sh *

Explanation: du -sh * shows disk usage (-s = summary per item, -h = human-readable) for files and directories in the current directory. df -h shows filesystem-level usage (mounted partitions).

Answer: c) Updates the access and modification timestamps

Explanation: touch updates the access and modification timestamps of an existing file to the current time. If the file doesn't exist, it creates an empty file by default (with -c it skips creation for non-existent files).

Answer: a) sort -n

Explanation: sort -n sorts values as numbers rather than strings. Without it, sort treats "10" as less than "2" (lexicographic sort). sort -g handles general numeric notation (floating point, scientific).

Answer: b) Number of words in "hello world"

Explanation: wc -w counts words. wc -l counts lines, wc -c counts bytes, and wc -m counts characters. The output would be 2 (two words: "hello" and "world").

Answer: d) Both ext4 and XFS, depending on distribution

Explanation: ext4 is the default for Debian/Ubuntu, while XFS is the default for RHEL/CentOS 7+. Both are supported by the kernel. ext3 is older and no longer the default for any major distribution.

Answer: b) Virtual filesystem for kernel and process data

Explanation: /proc/ is a virtual (pseudo) filesystem that provides information about the kernel, running processes, and hardware. It doesn't occupy disk space — files are generated on-the-fly by the kernel.

Answer: a) /var/

Explanation: /var/ contains variable data that persists between boots (logs, mail spools, databases, printer spools). /tmp/ is for temporary files that may be deleted on reboot. /run/ contains runtime variable data for running processes. /srv/ is for site-specific data served by the system.

Answer: d) Both a) and b)

Explanation: Both mkfs.ext4 /dev/sdb1 and mkfs -t ext4 /dev/sdb1 create an ext4 filesystem. The mkfs command uses -t to specify the filesystem type. mkfs.ext4 is a shorthand wrapper.

Answer: d) All of the above

Explanation: All three methods mount a filesystem as read-only. -o ro, -r, and --read-only are equivalent options. The most common is -o ro.

Answer: c) 16 TB

Explanation: The ext4 filesystem supports individual files up to 16 TB (with 4 KB block size) and a maximum filesystem size of 1 EB. XFS supports larger file sizes (8 EB), which is why it's preferred for large data workloads.

Answer: a) /etc/fstab

Explanation: /etc/fstab (filesystem table) defines filesystems and swap devices to be mounted at boot. Each entry includes device, mount point, filesystem type, options, dump frequency, and fsck pass order. /etc/mtab shows currently mounted filesystems.

Answer: b) Virtual memory — extending RAM to disk

Explanation: Swap provides virtual memory by paging out less-used memory pages to disk. This allows the system to run more applications than physical RAM alone can support. Swap can be a dedicated partition or a swap file.

Answer: a) /var/

Explanation: /var/ contains variable data that persists across reboots (logs, databases, mail spools, print queues, temporary files kept between reboots). /var/log/ specifically contains system log files like syslog, auth.log, and kern.log.

Answer: d) All of the above

Explanation: fsck.ext4, e2fsck, and fsck -t ext4 all invoke the ext4 filesystem checker. The filesystem must be unmounted (or mounted read-only) before running fsck. fsck is a frontend that dispatches to filesystem-specific checkers.

Answer: b) Specifies the interpreter to execute the script

Explanation: The shebang line (#!) tells the kernel which interpreter to use to execute the script. #!/bin/bash runs the script with the Bash shell. Common variants include #!/bin/sh, #!/usr/bin/python3, and #!/usr/bin/env bash.

Answer: b) The exit status of the last command

Explanation: $? holds the exit code of the most recently executed command. 0 means success, and any non-zero value indicates an error. Common special variables include $$ (PID), $# (argument count), $0 (script name), and $@ (all arguments).

Answer: a) chmod +x script.sh

Explanation: chmod +x adds execute permission to the file. After this, the script can be run as ./script.sh. bash script.sh runs it without making it executable. source script.sh runs it in the current shell environment.

Answer: b) Skips the rest of the current iteration and moves to the next

Explanation: continue skips the remaining code in the current loop iteration and moves to the next iteration. break exits the loop entirely. continue and break can take a numeric argument for nested loops (e.g., break 2).

Answer: d) All of the above

Explanation: All three iterators will loop over .txt files, but option a) is the most efficient and safest. Options b) and c) can break with filenames containing spaces (word splitting). Shell globbing (*.txt) is the recommended approach per LPIC-1 objectives.