LPIC-1 Practice Test 25 — 15 Questions

Question 1

An administrator wants to list all lines in a log file that do NOT contain the word 'ERROR'. Which command should be used?

Accepted Answer

grep -v 'ERROR' logfile. The `-v` flag inverts the match, causing `grep` to output only lines that do NOT contain the pattern 'ERROR'. This is the standard way to exclude lines matching a pattern in a file.

Answer

grep -i 'ERROR' logfile

Answer

grep -w 'ERROR' logfile

Answer

grep 'ERROR' logfile

Question 2

A systems administrator maintains a Linux web server running Apache HTTP Server (version 2.4) with three virtual hosts. The server logs are stored in /var/log/httpd/ and are rotated using logrotate, which is configured with the default settings that came with the Apache package. The administrator has noticed that after the nightly log rotation, the main access log file (access_log) is empty, while the rotated log files (e.g., access_log.1, access_log.2) contain the previous day's data. Furthermore, new HTTP requests are being logged into the most recent rotated file (access_log.1) instead of the current access_log file. The administrator has verified that the logrotate cron job runs successfully, and that the log files are owned by the root user with read/write permissions for the root group. No errors appear in the system logs. The Apache service continues to run and serve web pages. Which of the following actions should the administrator take to ensure that Apache writes new log entries to the current access_log file after rotation?

Accepted Answer

Add a postrotate script to the logrotate configuration that sends a USR1 or HUP signal to the Apache process to cause it to reopen the log files.. The issue is that after logrotate moves the current access_log to access_log.1, Apache continues writing to the old file descriptor (now pointing to access_log.1) because it never reopened the log file. Sending a USR1 or HUP signal to Apache causes it to close and reopen its log files, creating a new access_log and writing new entries there. This is the standard method for log rotation with Apache and other daemons that keep file handles open.

Answer

Modify the Apache configuration to set the 'RotateLogs' directive and restart the service.

Answer

Change the logrotate frequency to 'weekly' so that the log is not rotated as often.

Answer

Set the 'copytruncate' directive in the logrotate configuration to copy the log file and truncate the original, so Apache can continue writing without interruption.

Question 3

A Linux administrator is responsible for a server that runs a critical database application. The server uses SysV init and the current runlevel is 3. The administrator needs to schedule a maintenance window for next Sunday at 2:00 AM to apply security patches that require a reboot. The administrator wants to ensure that after the reboot, the system returns to runlevel 3 and the database service (db_service) starts automatically. The administrator also wants to log the maintenance actions to /var/log/maintenance.log. Which of the following is the BEST approach to accomplish these tasks?

Accepted Answer

Edit /etc/rc.d/rc.local to start db_service and set runlevel via 'init 3' in the script. Then use 'at 2am Sunday shutdown -r now' to schedule reboot and redirect output to /var/log/maintenance.log.. The best approach because it uses 'at' to schedule the reboot, which can be configured to run at a specific day and time (e.g., 'at 2am Sunday shutdown -r now'), and redirects output to /var/log/maintenance.log for simple logging. Although editing rc.local is not the standard SysV method for persistent service management, it effectively starts the database service and sets the runlevel to 3 upon boot. In contrast, option B's shutdown command does not allow specifying the day 'next Sunday', and configuring syslog for a custom log file is non-trivial. Options C and D are incorrect due to systemd usage or lack of scheduling.

Answer

Edit /etc/inittab to change the initdefault line to 'id:3:initdefault:' and create an init script for db_service with appropriate symlinks in /etc/rc.d/rc3.d/. Schedule the reboot using 'shutdown -r 02:00' and configure syslog to capture messages to /var/log/maintenance.log.

Answer

Use 'systemctl set-default runlevel3.target' and 'systemctl enable db_service' then schedule reboot with 'shutdown -r 02:00' and log with 'logger' to /var/log/maintenance.log.

Answer

Use 'telinit 3' and 'service db_service start' then run 'reboot' at 2:00 AM. Log actions by appending to /var/log/maintenance.log manually.

Question 4

After receiving a compressed tarball archive.tar.gz from a colleague, you want to list its contents without extracting. Which command should you use?

Accepted Answer

tar -tvf archive.tar.gz. The `tar -tvf archive.tar.gz` command lists the contents of a compressed tarball without extracting it. The `-t` option tells tar to list the archive's table of contents, `-v` provides verbose output (showing file permissions, ownership, etc.), and `-f` specifies the archive file. Tar automatically detects and decompresses the gzip compression when reading the file, so no separate decompression step is needed.

Answer

tar -xzf archive.tar.gz

Answer

tar -cvf archive.tar.gz

Answer

gzip -d archive.tar.gz | tar -t

Question 5

A technician is troubleshooting a system that fails to boot with the error 'Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)'. What is the most likely cause?

Accepted Answer

The kernel lacks the necessary driver for the storage controller.. The error 'VFS: Unable to mount root fs on unknown-block(0,0)' indicates that the kernel cannot locate or access the root filesystem. This typically occurs because the kernel lacks the necessary driver (module) for the storage controller (e.g., SATA, SCSI, NVMe) that the root device is connected to, so it cannot read the partition table or mount the root filesystem.

Answer

The init binary is missing or corrupted.

Answer

The root filesystem is corrupted and needs fsck.

Answer

The boot loader is not installed correctly.

Question 6

A Linux server has two hot-swappable SATA drives that are part of a software RAID 1 array. The administrator needs to replace one drive while the system is running, but first wants to verify the current status of the array to ensure it is not degraded. Which command will display the detailed status of the mdadm array?

Accepted Answer

mdadm --detail /dev/md0. To verify the status of a software RAID array before replacing a drive, the administrator needs detailed information about the array's health and component devices. The mdadm --detail command provides this comprehensive view, including RAID level, state, and per-device status. This ensures the array is not already degraded and that the correct drive can be identified for replacement. Other commands either show only summary information or focus on physical drives rather than the RAID logical device.

Answer

cat /proc/mdstat

Answer

smartctl -a /dev/sda

Answer

fdisk -l /dev/sda

Question 7

An administrator needs to mount an ISO image located at /tmp/install.iso to the directory /mnt/iso. Which command will accomplish this?

Accepted Answer

mount -o loop /tmp/install.iso /mnt/iso. Mounting an ISO image requires the loop option to associate the file with a loop device, which the kernel then treats as a block device. The mount command with -o loop is the correct syntax. Other options either omit loop, use bind incorrectly, or attempt to remount a non-mounted filesystem.

Answer

mount --bind /tmp/install.iso /mnt/iso

Answer

mount -o remount,loop /tmp/install.iso /mnt/iso

Answer

mount -t iso9660 /tmp/install.iso /mnt/iso

Question 8

A technician needs to identify the hardware installed on a Linux workstation. The technician runs a command that prints a hierarchical tree of PCI devices showing vendor and device IDs, along with the kernel driver in use. Which command was most likely executed?

Accepted Answer

lspci -k. The lspci utility enumerates PCI devices, and its -k option adds the kernel driver and modules handling each device. That combination directly satisfies the need to see a PCI device tree with vendor/device IDs and driver information. Storage, USB, and DMI tools cover other hardware classes and do not provide the required PCI driver mapping.

Answer

dmidecode -t memory

Answer

lsblk -f

Answer

lsusb -t

Question 9

A Linux administrator needs to determine which kernel modules are currently loaded on a running system. The administrator also wants to see the module dependencies and the use count for each module. Which command should be used?

Accepted Answer

lsmod. lsmod queries the kernel's loaded module list by reading /proc/modules and presents each module with its memory size, use count, and dependencies. That output lets an administrator confirm whether a needed driver is active and whether it is in use. Tools like modinfo and depmod operate on module files and metadata, not on the runtime state of loaded modules.

Answer

depmod

Answer

modprobe -l

Answer

modinfo

Question 10

A Linux server has a USB serial adapter that is sometimes detected as /dev/ttyUSB0 and sometimes as /dev/ttyUSB1 after reboot. An administrator wants to create a udev rule that always assigns the name /dev/ttyUSB-radio to this specific adapter based on its serial number. Which udev rule syntax should be used?

Accepted Answer

SUBSYSTEM=="tty", ATTRS{serial}=="A50285BI", SYMLINK+="ttyUSB-radio". A reliable udev rule for a USB serial adapter must match the tty subsystem and a unique attribute such as the adapter's serial number, then create a persistent symlink. ATTRS{serial} searches the device and its parent devices, which is where USB serial numbers are exposed. SYMLINK+ adds the link without disturbing other symlinks, ensuring the adapter is always reachable at /dev/ttyUSB-radio.

Answer

KERNEL=="ttyUSB*", ATTR{idVendor}=="0403", SYMLINK="ttyUSB-radio"

Answer

SUBSYSTEM=="usb", ATTR{serial}=="A50285BI", NAME="ttyUSB-radio"

Answer

ACTION=="add", SUBSYSTEM=="tty", RUN+="/bin/ln -s /dev/%k /dev/ttyUSB-radio"

Question 11

An administrator needs to inspect the hardware inventory of a server, including details about the motherboard, BIOS, and memory banks, in a structured way. Which command provides this information by reading from the DMI/SMBIOS data?

Accepted Answer

dmidecode. The DMI/SMBIOS table is firmware-provided data describing the physical platform. dmidecode decodes that table directly, yielding sections for BIOS, system, baseboard, and memory devices including individual slots. Commands that enumerate buses such as PCI or USB describe attached devices instead, and general-purpose inventory tools aggregate data rather than decoding the firmware table itself.

Answer

lsusb

Answer

lspci

Answer

lshw

Question 12

A junior administrator needs to install the package 'nginx' on an Ubuntu 22.04 server. They download the nginx_1.18.0-6ubuntu14.4_amd64.deb file from a vendor website and run the command 'dpkg -i nginx_1.18.0-6ubuntu14.4_amd64.deb'. The installation fails with an error stating that the package depends on 'libnginx-mod-http-image-filter'. Which command should the administrator run next to resolve the missing dependency?

Accepted Answer

apt-get install -f. When dpkg fails to install a .deb file because of unmet dependencies, the package remains unconfigured and the system package database becomes inconsistent. The recommended fix is to run 'apt-get install -f', which instructs APT to resolve broken dependencies by downloading and installing required packages from the repositories. This restores system consistency and completes the installation.

Answer

dpkg -i --force-depends nginx_1.18.0-6ubuntu14.4_amd64.deb

Answer

apt-get update

Answer

dpkg --configure -a

Question 13

A Linux administrator runs df -h and sees that the /var filesystem is 100% full. The administrator deletes several large log files, but df still shows 100% usage. Which command should the administrator use to identify processes that are holding deleted files open?

Accepted Answer

lsof +L1. When a file is deleted but still open by a process, the directory entry is removed, but the inode and data blocks remain allocated until the process closes the file. df reflects the actual blocks allocated, while du only sees directory entries. lsof +L1 lists open files with link count less than 1, identifying deleted files still in use. Restarting the holding process releases the space.

Answer

fdisk -l /dev/sda

Answer

fsck /dev/sda1

Answer

du -sh /var

Question 14

A system administrator needs to ensure that a custom kernel module named 'mydriver.ko' is loaded automatically at boot on a system that uses systemd. The module is located in /lib/modules/$(uname -r)/extra/. Which approach is most appropriate?

Accepted Answer

Create a file /etc/modules-load.d/mydriver.conf containing the line 'mydriver'.. On systemd-based systems, the systemd-modules-load service is responsible for loading modules at boot based on configuration files in /etc/modules-load.d/, /run/modules-load.d/, and /usr/lib/modules-load.d/. Creating a .conf file with the module name in /etc/modules-load.d/ is the correct, supported method. Other approaches may work incidentally but are not the intended mechanism.

Answer

Add the line 'mydriver' to /etc/modules.

Answer

Insert the module into the initramfs using 'mkinitrd' and rely on it being loaded during early boot.

Answer

Run 'modprobe mydriver' and add it to /etc/rc.local.

Question 15

A Linux administrator is troubleshooting a server that intermittently fails to detect a newly installed network card. The administrator suspects the kernel is not loading the correct driver automatically. Which TWO commands should be used to identify the PCI device and then load the appropriate kernel module manually? (Choose two.)

Accepted Answer

lspci -nn. To resolve an undetected PCI network card, the administrator must first identify the device with lspci -nn to obtain numeric vendor and device IDs, then load the matching driver with modprobe. This sequence confirms the hardware presence and activates the correct kernel module, after which the interface should appear. USB inspection, interface listing, and module removal do not address a missing PCI driver.

Answer

rmmod

Answer

ifconfig -a

Answer

lsusb -v