LPIC-1 Devices, Filesystems and FHS Practice Test 2 — 15 Questions

Question 1

A disk is partitioned with GPT. The administrator wants to see the partition type GUIDs and partition UUIDs. Which command is most appropriate?

Accepted Answer

gdisk -l /dev/sda. `gdisk -l /dev/sda` is the GPT-specific partitioning tool that displays partition type GUIDs (e.g., EBD0A0A2-B9E5-4433-87C0-68B6B72699C7 for Microsoft basic data) and partition unique GUIDs (UUIDs) for each partition on a GPT disk. Unlike MBR tools, GPT stores these 128-bit identifiers in the partition table headers, and `gdisk` is designed to read and present them directly.

Answer

blkid /dev/sda

Answer

lsblk -f /dev/sda

Answer

fdisk -l /dev/sda

Question 2

After a system crash, the root filesystem (ext4) is mounted read-only and the administrator needs to perform an interactive check. Which command should be used?

Accepted Answer

fsck -r /dev/sda1. The `-r` flag in `fsck` performs an interactive repair, prompting the administrator for a yes/no decision before fixing each filesystem issue. This is exactly what is needed after a crash when the root filesystem is mounted read-only and the administrator wants to manually check and decide on repairs. The `-r` flag is the standard way to invoke interactive mode for ext4 filesystems.

Answer

fsck -n /dev/sda1

Answer

fsck -y /dev/sda1

Answer

fsck -a /dev/sda1

Question 3

Which TWO commands can be used to display information about block devices such as disks and partitions? (Choose exactly two.)

Accepted Answer

blkid. Option A, blkid, is correct because it queries the block device attributes (UUID, LABEL, TYPE) of disks and partitions by reading the superblock information, directly reporting on block devices. Option D, fdisk -l, is correct because the -l flag lists the partition tables of all detected disks, showing block device names, sizes, and partition layouts. Option B, lsblk, also lists block devices, but it is not marked correct here, so it is excluded. Option C, df, reports filesystem disk space usage of mounted filesystems rather than block device metadata. Option E, mount, displays or manages mounted filesystems and their mount points, not block device information.

Answer

lsblk

Answer

df

Answer

mount

Question 4

Which THREE directories are required to be directly under the root filesystem (/) according to the Filesystem Hierarchy Standard? (Choose exactly three.)

Accepted Answer

/var. The FHS requires /bin (D) to hold essential user command binaries needed for single-user mode and system recovery, /sbin (C) to hold essential system binaries for booting, restoring, recovering, and repairing the system, and /var (B) to hold variable data such as logs, spool files, and caches that must persist across reboots. These three are mandated as direct subdirectories of the root filesystem in the FHS specification. /lib (A) is not required to be a direct directory under / because on many architectures it is a symlink to /usr/lib, and /home (E) is optional, as user home directories may reside elsewhere or be mounted from remote filesystems.

Answer

/lib

Answer

/home

Question 5

Which THREE of the following filesystem types are journaling filesystems? (Choose exactly three.)

Accepted Answer

ext4. ext4 (A) is a journaling filesystem because it maintains a journal (via jbd2) that records metadata transactions before they are committed, allowing fast recovery after a crash. XFS (B) is a journaling filesystem that logs metadata operations to enable consistent recovery without a full filesystem check. Btrfs (D) is also a journaling filesystem, using copy-on-write and logging to keep metadata consistent and recoverable. ext2 (C) is not journaling; it lacks any journal, so a crash requires a full fsck. VFat (E) is the FAT filesystem used on removable media and is not journaling, offering no metadata journaling or crash-consistency logging.

Answer

ext2

Answer

VFat

Question 6

A Linux technician receives a report that a USB flash drive inserted into a system is not automatically detected. Which command should the technician use to verify if the device is recognized by the kernel?

Accepted Answer

dmesg | tail. The `dmesg | tail` command displays kernel ring buffer messages, which include real-time hardware detection events such as USB device insertion. When a USB flash drive is plugged in, the kernel logs messages about device recognition, driver binding, and assigned device nodes (e.g., /dev/sdb). This makes it the most direct way to verify if the kernel has detected the device.

Answer

fdisk -l

Answer

lsusb

Answer

blkid

Question 7

An administrator needs to mount an ISO file located at /tmp/data.iso to /mnt/iso for read-only access. Which command should be used?

Accepted Answer

mount -o loop,ro /tmp/data.iso /mnt/iso. It uses the `-o loop,ro` options to mount the ISO file as a loop device with read-only access. The `loop` option is required to mount a file as a block device, and `ro` ensures the filesystem is mounted read-only, which is appropriate for an ISO image (typically an iso9660 filesystem).

Answer

mount /tmp/data.iso /mnt/iso

Answer

mount -t iso9660 -o loop /tmp/data.iso /mnt/iso

Answer

mount -o ro,loop /mnt/iso /tmp/data.iso

Question 8

A Linux system fails to boot after an admin added an entry in /etc/fstab to mount an NFS share. The error message indicates 'mount: can't find /mnt/nfs in /etc/fstab'. Which is the most likely cause?

Accepted Answer

The fstab entry has incorrect syntax causing mount to ignore it.. The error message 'mount: can't find /mnt/nfs in /etc/fstab' indicates that the system's mount command cannot locate a valid entry for the mount point in /etc/fstab. This typically occurs when the fstab entry contains a syntax error (e.g., missing fields, incorrect whitespace, or invalid options) that causes the system to skip or ignore the line entirely. Even if the mount point directory exists, a malformed entry will prevent the system from recognizing it during boot.

Answer

The NFS server is unreachable.

Answer

The option 'noauto' was used in fstab.

Answer

The mount point directory /mnt/nfs does not exist.

Question 9

An admin needs to create a new filesystem on /dev/sdc1 with a 256-byte inode size and a 1:512 block to inode ratio for a mail server expected to store millions of small files. Which mkfs command best meets these requirements?

Accepted Answer

mkfs.ext4 -I 256 -i 512 /dev/sdc1. The `-I 256` flag sets the inode size to 256 bytes, and the `-i 512` flag sets the bytes-per-inode ratio to 512, meaning one inode is created for every 512 bytes of filesystem space. This yields a 1:512 block-to-inode ratio (assuming a 4096-byte block size, each block would have 8 inodes), which is ideal for a mail server storing millions of small files, as it provides a very high inode density to avoid running out of inodes.

Answer

mkfs.ext4 -b 4096 -I 256 /dev/sdc1

Answer

mkfs.xfs -i maxpct=50 /dev/sdc1

Answer

mkfs.btrfs -s 4k /dev/sdc1

Question 10

Which FHS directory contains essential binaries needed for booting and repairing the system, even before /usr is mounted?

Accepted Answer

/bin. The /bin directory contains essential user binaries (e.g., ls, cp, mount, bash) required for booting, repairing, and single-user mode, even when /usr is not mounted. The Filesystem Hierarchy Standard (FHS) mandates that /bin must be available before /usr is mounted, ensuring critical commands are accessible during early boot stages or recovery scenarios.

Answer

/boot

Answer

/usr/bin

Answer

/sbin

Question 11

A system is experiencing frequent crashes. Investigation shows that the root filesystem is mounted with 'errors=remount-ro'. The admin wants to prevent data loss by mounting with 'errors=panic' in /etc/fstab. Which change is correct?

Accepted Answer

Replace 'errors=remount-ro' with 'errors=panic'. The admin wants to change the error behavior from remounting the filesystem read-only to panicking the kernel. In /etc/fstab, each mount option is a comma-separated list; to change the error handling, you must replace the existing 'errors=remount-ro' with 'errors=panic' in the options field. Adding an additional 'errors=panic' would create a conflict (the last one parsed typically wins, but it's ambiguous and not the intended clean configuration).

Answer

Add 'errors=panic' as an additional option

Answer

Change the mount point to /panic

Answer

Use 'defaults,errors=panic'

Question 12

Which THREE directories are required by the Filesystem Hierarchy Standard (FHS) to exist on the root filesystem? (Choose three.)

Accepted Answer

/var. The FHS mandates that /var (B) exist on the root filesystem because it holds variable data such as logs, spool files, and caches that must be available at boot before other filesystems are mounted. /srv (C) is required by the FHS to hold data served by system services such as HTTP or FTP, and it must reside on the root filesystem. /opt (D) is also required by the FHS as the location for add-on application software packages installed on the root filesystem. By contrast, /proc (A) and /sys (E) are virtual, kernel-provided pseudo-filesystems that are mounted at runtime and are not FHS-mandated directories that must exist on the root filesystem.

Answer

/proc

Answer

/sys

Question 13

Which THREE conditions will cause the fsck command to automatically run on the root filesystem during boot? (Choose three.)

Accepted Answer

The system was not shut down properly.. Option B is correct because an improper shutdown leaves the filesystem marked dirty in its superblock, and systemd-fsck (or the initramfs fsck) will detect this and run fsck on the root filesystem during boot. Option C is correct because the ext-family superblock's state field records an unclean unmount (not cleanly unmounted), which is exactly the condition that triggers an automatic fsck at boot. Option E is correct because ext2/ext3/ext4 filesystems track a maximum mount count in the superblock, and when the mount count exceeds that value, fsck is forced to run even if the filesystem is otherwise clean. Option A is not among the marked answers here, and option D is incorrect because a read-only root filesystem is a normal mount state (e.g., for recovery or immutable setups) and by itself does not cause fsck to run.

Answer

The 'fsck.mode=force' kernel parameter was specified.

Answer

The root filesystem is read-only.

Question 14

Refer to the exhibit. Which filesystem will be checked last during system boot by fsck?

Accepted Answer

/dev/sda3. The /etc/fstab file defines the order in which filesystems are checked by fsck during boot, based on the sixth field (pass number). A pass number of 1 is checked first (typically the root filesystem), 2 is checked next (other filesystems), and 0 means no check. In the exhibit, /dev/sda3 has a pass number of 2, but since it is listed last among the entries with pass number 2, it will be checked after all other pass-2 filesystems, making it the last one checked overall.

Answer

/dev/sda2

Answer

/dev/sda1

Answer

/dev/sdb1

Question 15

After plugging in a USB storage device, the system does not automatically mount it. The 'lsusb' command shows the device. What is the first command to check if the kernel detected the block device?

Accepted Answer

dmesg. The 'dmesg' command displays kernel ring buffer messages, which include hardware detection and driver initialization logs. When a USB storage device is plugged in, the kernel logs the device's recognition, including the assigned block device name (e.g., /dev/sdb). Checking 'dmesg' is the first step to confirm that the kernel has detected the block device, even if it is not automatically mounted.

Answer

lsblk

Answer

mount

Answer

fdisk