LPIC-1 System Architecture — Timed 20 Questions

Question 1

A system administrator notices that the server's clock is consistently off by several minutes. Which service should be used to synchronize the time with an external time source?

Accepted Answer

ntpd. The Network Time Protocol (NTP) daemon (ntpd) is the traditional and widely used service for synchronizing a server's clock with an external time source. It continuously adjusts the system time by communicating with NTP servers, compensating for clock drift and network delays to maintain accurate time. This makes ntpd the correct choice for resolving a consistent clock offset of several minutes.

Answer

timed

Answer

chronyd

Answer

systemd-timesyncd

Question 2

During boot, the kernel must mount the root filesystem. Which of the following is responsible for providing the kernel with the location of the root filesystem?

Accepted Answer

boot loader. The boot loader (e.g., GRUB) is responsible for loading the kernel into memory and passing it the location of the root filesystem via kernel command-line parameters such as `root=`. Without this parameter, the kernel would not know which block device or partition to mount as `/`. The boot loader reads configuration files (e.g., `grub.cfg`) that specify this parameter, making it the direct provider of the root filesystem location.

Answer

udev

Answer

initramfs

Answer

init

Question 3

An administrator needs to ensure that a specific kernel module is loaded automatically at boot. Which file should be used to permanently load the module?

Accepted Answer

/etc/modules. On modern Linux systems using a standard init system, the file /etc/modules (or /etc/modules-load.d/*.conf on systemd-based distributions) is read at boot to load specified kernel modules automatically. This file lists module names one per line, and the kernel's module loading mechanism processes it early in the boot sequence to ensure the module is available before services that depend on it start.

Answer

/etc/modprobe.d/modules.conf

Answer

/etc/sysconfig/modules

Answer

/etc/conf.modules

Question 4

Refer to the exhibit. The system has a single disk with three partitions. Which partition contains the root filesystem?

Accepted Answer

sda3. The root filesystem is mounted from the partition that contains the / (root) directory. In Linux, partitions are numbered starting from 1 (e.g., sda1, sda2, sda3). The device sda itself refers to the entire disk, not a partition. Since the system has three partitions and the correct answer is sda3, partition sda3 must be the one designated as the root filesystem, typically identified by the mount point '/' in /etc/fstab or by the kernel boot parameter root=.

Answer

sda

Answer

sda1

Answer

sda2

Question 5

Refer to the exhibit. How many SATA controllers are detected, and what is the connection speed of the SSD?

Accepted Answer

2 controllers; SSD at 6.0 Gbps. The output from `lspci` shows two SATA controllers: one identified as 'SATA controller: Intel Corporation 82801IBM/IEM (ICH9M/ICH9M-E) 4 port SATA Controller' and another as 'SATA controller: Intel Corporation 82801IBM/IEM (ICH9M/ICH9M-E) 2 port SATA Controller'. The SSD is connected to the 6 Gbps port, as indicated by the '6 Gbps' label in the device listing, confirming a 6.0 Gbps connection speed.

Answer

3 controllers; SSD at 6.0 Gbps

Answer

2 controllers; SSD at 3.0 Gbps

Answer

1 controller; SSD at 6.0 Gbps

Question 6

A Linux administrator manages a server that runs a custom application requiring a specific kernel module to be loaded at boot. The server uses SysV init and has the module listed in /etc/modules. However, after a recent kernel update, the module fails to load automatically at boot. The administrator can manually load the module with 'modprobe <module>' after the system is running. The application depends on this module being loaded before any network services start. Which of the following actions should the administrator take to ensure the module loads automatically at the correct time during boot?

Accepted Answer

Create a SysV init script that loads the module and place it in /etc/init.d/ with appropriate symlinks in /etc/rc?.d/ to ensure it runs before network services.. SysV init systems use init scripts in /etc/init.d/ with symlinks in /etc/rc?.d/ to control the order of service startup. By creating a custom init script that loads the module via modprobe and placing it with a symlink that has a lower number (e.g., S01module) than network services (e.g., S10network), the module will be loaded before network services start, satisfying the application's dependency.

Answer

Add the module name to /etc/modules-load.d/ directory.

Answer

Add an install directive in /etc/modprobe.d/ for the module.

Answer

Add a blacklist entry for the module in /etc/modprobe.d/blacklist.conf.

Question 7

Arrange the steps to configure a firewall rule using iptables to allow SSH.

Accepted Answer

Step 1: Add the SSH allow rule using iptables (e.g., iptables -A INPUT -p tcp --dport 22 -j ACCEPT). Step 2: Save the current iptables rules to a file (e.g., iptables-save > /etc/iptables/rules.v4). Step 3: Install and enable iptables-persistent to load rules on boot.. iptables rules are added, then saved to a file, and persistence ensures they survive reboot.

Answer

Step 1: Save the current iptables rules to a file. Step 2: Add the SSH allow rule. Step 3: Install and enable iptables-persistent.

Answer

Step 1: Add the SSH allow rule. Step 2: Install and enable iptables-persistent. Step 3: Save the current iptables rules.

Answer

Step 1: Install and enable iptables-persistent. Step 2: Add the SSH allow rule. Step 3: Save the current iptables rules.

Question 8

Which command displays the system's architecture (e.g., x86_64)?

Accepted Answer

All of the above. ('All of the above') is correct because each of the listed commands—lscpu, arch, and uname -m—can display the system's architecture (e.g., x86_64). lscpu parses /proc/cpuinfo to show architecture details, arch prints the machine hardware name directly, and uname -m outputs the kernel's machine hardware name, all of which report the same architecture identifier on a given system.

Answer

lscpu

Answer

arch

Answer

uname -m

Question 9

A system administrator needs to create a new Logical Volume (LV) in an existing LVM setup. Which sequence of commands is correct?

Accepted Answer

pvcreate, vgcreate, lvcreate. The correct sequence is pvcreate, vgcreate, lvcreate because in LVM, you must first initialize physical volumes (PVs) with pvcreate, then combine them into a volume group (VG) with vgcreate, and finally create the logical volume (LV) from the VG's free space with lvcreate. This order reflects the dependency chain: a VG requires PVs, and an LV requires a VG.

Answer

vgcreate, pvcreate, lvcreate

Answer

pvcreate, lvcreate, vgcreate

Answer

lvcreate, vgcreate, pvcreate

Question 10

A sysadmin wants to ensure a specific kernel module is automatically loaded at boot. Which method is considered best practice?

Accepted Answer

Add module name to /etc/modules. The best practice to automatically load a kernel module at boot is to add the module name to /etc/modules or a file in /etc/modules-load.d/. This method works on both sysvinit and systemd systems, as systemd-modules-load.service reads these configuration files. Directly using the service or adding lines to /etc/modprobe.d/ is not standard; /etc/modprobe.d/ is for module options, not auto-loading.

Answer

Use systemd-modules-load.service

Answer

All of the above are valid methods

Answer

Add a line to /etc/modprobe.d/

Question 11

During boot, a sysadmin sees the message 'Buffer I/O error on device sda1, logical block 0'. What does this most likely indicate?

Accepted Answer

Bad sector on the disk. The 'Buffer I/O error on device sda1, logical block 0' message indicates that the kernel's block layer failed to read or write the first logical block (LBA 0) of the partition. This is a classic symptom of a physical bad sector on the disk surface, as the storage medium itself cannot reliably store or retrieve data at that location. Filesystem corruption or partition table issues would typically produce different error messages, such as 'invalid superblock' or 'partition table invalid'.

Answer

Incorrect partition table

Answer

Filesystem corruption

Answer

Missing kernel module for the device

Question 12

Which TWO files are used to configure kernel boot parameters in GRUB?

Accepted Answer

/etc/default/grub. The two correct answers are B (/etc/default/grub) and C (/etc/grub.d/). /etc/default/grub is the primary user-editable configuration file where variables such as GRUB_CMDLINE_LINUX and GRUB_CMDLINE_LINUX_DEFAULT are set to define kernel boot parameters. /etc/grub.d/ contains executable scripts (e.g., 10_linux, 40_custom) that generate the GRUB menu entries and can inject kernel command-line arguments into the final configuration. Together, these files are the source inputs used by grub-mkconfig (or update-grub) to build the bootloader configuration. Option A (/sys/kernel/cmdline) and option D (/proc/cmdline) are read-only runtime interfaces that merely report the parameters the currently running kernel was booted with, not configuration files. Option E (/boot/grub/grub.cfg) is the generated output file that should not be edited directly, as changes would be overwritten the next time grub-mkconfig runs.

Answer

/sys/kernel/cmdline

Answer

/proc/cmdline

Answer

/boot/grub/grub.cfg

Question 13

Which THREE of the following are valid systemd targets?

Accepted Answer

poweroff.target. poweroff.target (A) is a valid systemd target that powers off the system, and it is one of the standard targets shipped with systemd. reboot.target (C) is likewise a valid systemd target used to restart the machine. halt.target (D) is also a valid systemd target that halts the system without powering it off. rescue.target (B) is a real systemd target, but it is not marked as correct here, and shutdown.target (E) is actually an internal systemd target used to terminate services during shutdown rather than a user-facing target, so neither belongs in the marked set.

Answer

rescue.target

Answer

shutdown.target

Question 14

The system administrator wants to use the entire sdb disk as a single partition. Which command will partition sdb with a single partition occupying the whole disk?

Accepted Answer

parted /dev/sdb mklabel gpt && parted /dev/sdb mkpart primary 0% 100%. It uses parted to first create a GPT partition table on /dev/sdb (mklabel gpt) and then creates a single primary partition spanning the entire disk (mkpart primary 0% 100%). This is the proper method to partition the whole disk as one partition, ensuring the disk has a valid partition table and a defined partition that can later be formatted.

Answer

fdisk /dev/sdb, then create a new primary partition accepting all defaults

Answer

dd if=/dev/zero of=/dev/sdb bs=1M count=1

Answer

mkfs.ext4 /dev/sdb

Question 15

A kernel module fails to load with the error 'modprobe: FATAL: Module xyz not found in directory /lib/modules/$(uname -r)'. What is the most likely cause?

Accepted Answer

The kernel version has changed and modules need to be rebuilt.. The error message references the specific kernel version from `uname -r`. If the kernel has been updated (e.g., via a package upgrade), the modules directory for the new kernel version will not contain the previously built modules. The module must be rebuilt against the new kernel's source or headers, which is why option B is correct.

Answer

The module is blacklisted in /etc/modprobe.d/.

Answer

The module has dependencies that are missing.

Answer

The module is not installed on the system.

Question 16

After modifying the /etc/fstab file, an administrator runs the command mount -a and receives the error 'mount: /data: special device /dev/sdb1 does not exist'. What is the most likely issue?

Accepted Answer

There is a typo in the device path in /etc/fstab.. The `mount -a` command reads all entries in /etc/fstab and attempts to mount them. The error 'special device /dev/sdb1 does not exist' indicates that the kernel cannot find the block device file at that path. The most likely cause is a typographical error in the device path within /etc/fstab, such as a misspelling (e.g., /dev/sdb1 vs /dev/sdb1) or an incorrect partition number, because the device file itself is created by udev and would exist if the hardware were properly detected.

Answer

The /dev/sdb1 device file is missing or corrupted.

Answer

The entry in /etc/fstab has an incorrect filesystem type.

Answer

The filesystem on /dev/sdb1 is not formatted.

Question 17

Which TWO commands can be used to display information about the CPU(s) in a Linux system? (Choose two.)

Accepted Answer

cat /proc/cpuinfo. Option D, cat /proc/cpuinfo, is correct because the /proc/cpuinfo virtual file is generated by the kernel and exposes detailed per-core CPU data such as vendor_id, model name, cpu MHz, cache size, and flags, so reading it displays CPU information. Option E, lscpu, is correct because it is a util-linux command that reads /proc/cpuinfo and /sys to present a summarized, human-readable report of CPU architecture, sockets, cores per socket, threads per core, model name, and virtualization support. Option A, uname -m, only prints the machine hardware architecture (for example x86_64 or aarch64) and does not report CPU details like model, cores, or frequency. Option B, lsusb, enumerates USB buses and connected USB devices, which is unrelated to CPU information. Option C, cpufreq-info, reports CPU frequency scaling policy and driver details, but it is not one of the two expected general CPU-information commands and is not marked correct here.

Answer

uname -m

Answer

lsusb

Answer

cpufreq-info

Question 18

Which TWO conditions would cause the boot process to fall back to the GRUB rescue shell? (Choose two.)

Accepted Answer

The GRUB modules are not loaded from the correct path.. The GRUB rescue shell is entered when the core image cannot locate its modules, typically due to an incorrect module path. This prevents GRUB from loading its normal configuration, causing a fallback to the minimal rescue shell. Missing or corrupt grub.cfg, on the other hand, leads to the GRUB normal shell (grub>), not the rescue shell. Other issues like missing kernel, initramfs, or BIOS failure occur after GRUB or before it starts, so they do not trigger the rescue shell.

Answer

The kernel image is not found in /boot.

Answer

The BIOS cannot find a bootable device.

Answer

The initramfs is missing or corrupt.

Answer

The /boot/grub/grub.cfg file is missing or corrupt.

Question 19

Which THREE of the following are valid runlevels in a traditional SysV init system? (Choose three.)

Accepted Answer

6. In a traditional SysV init system, runlevels are numbered 0 through 6, so option B (6) is valid as the reboot runlevel, option D (1) is valid as single-user/rescue mode, and option E (0) is valid as the halt/shutdown runlevel. These three values fall within the standard seven defined runlevels (0–6) used by SysV init. Options A (9) and C (7) are not valid SysV runlevels because the numbering stops at 6; values above 6 are not defined in the traditional SysV init scheme.

Answer

9

Answer

7

Question 20

Refer to the exhibit. How many physical disks are detected by the kernel, and what are their sizes?

Accepted Answer

Two disks: sda 10.0 GiB, sdb 2.00 GiB. The kernel has detected two physical disks: /dev/sda with a capacity of 10.0 GiB and /dev/sdb with a capacity of 2.00 GiB. This is evident from the output of `fdisk -l`, which lists disk devices and their sizes in gibibytes (GiB), a binary-based unit where 1 GiB = 1024^3 bytes. The kernel enumerates SCSI/SATA disks as /dev/sdX, and the output shows exactly two such devices.

Answer

Two disks: sda 10.7 GB, sdb 2.15 GB

Answer

Three disks: sda, sdb, and an unknown device

Answer

One disk: sda 10.7 GB