LPIC-1 Devices, Filesystems and FHS Practice Test 4 — 15 Questions

Question 1

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 2

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 3

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 4

An admin runs 'lsblk' and sees that /dev/nvme0n1p1 is listed with size 512M and mounted at /boot/efi. What is the most likely filesystem type?

Accepted Answer

vfat. The /boot/efi partition is the EFI System Partition (ESP), which is required for UEFI boot. The ESP must be formatted with a FAT-based filesystem (typically vfat/FAT32) because the UEFI firmware is designed to read FAT partitions to load boot loaders. The size of 512M is also typical for an ESP.

Answer

ext4

Answer

swap

Answer

xfs

Question 5

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 6

Which TWO commands can be used to display the UUID of a filesystem? (Choose two.)

Accepted Answer

lsblk -f. The `lsblk -f` command lists block devices and includes the filesystem UUID in its output, making it a valid tool for displaying UUIDs. The `blkid` command directly queries and displays UUIDs and other attributes of block devices, so it is also correct.

Answer

df -h

Answer

mount

Answer

cat /etc/fstab

Question 7

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

Accepted Answer

/var. The Filesystem Hierarchy Standard (FHS) mandates that /var, /srv, and /opt must exist on the root filesystem. /var contains variable data such as logs and spools, /srv holds site-specific service data, and /opt is reserved for add-on application software packages. These directories are explicitly listed as required in the FHS specification.

Answer

/proc

Answer

/sys

Question 8

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.. When the system was not shut down properly (e.g., due to a power failure or crash), the root filesystem is marked as 'dirty' in its superblock. During the next boot, fsck detects this condition and automatically runs a filesystem check on the root partition to ensure consistency before mounting it.

Answer

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

Answer

The root filesystem is read-only.

Question 9

Refer to the exhibit. How much unpartitioned space is available on /dev/sda?

Accepted Answer

5.5G. The output of `fdisk -l /dev/sda` shows partitions sda1 (0.5G), sda2 (100G), and sda3 (150G), summing to 250.5G. The total disk size is 256G, so the unpartitioned space is 256G - 250.5G = 5.5G. Candidates often misread the partition sizes or add them incorrectly, leading to wrong answers.

Answer

256G

Answer

6G

Answer

150G

Question 10

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 11

Refer to the exhibit. An admin attempts to execute a shell script located in /tmp but gets 'Permission denied'. Which mount option is most likely causing this?

Accepted Answer

noexec. The 'noexec' mount option prevents execution of any binary or script directly from the filesystem, regardless of file permissions. Since the script is in /tmp and the admin gets 'Permission denied' despite correct execute bits, the /tmp partition is likely mounted with noexec, which is a common security hardening practice.

Answer

relatime

Answer

nodev

Answer

nosuid

Question 12

A system administrator wants to install custom scripts that should be available to all users. The scripts are not part of any package and should be placed under the Filesystem Hierarchy Standard (FHS). Which directory is most appropriate?

Accepted Answer

/usr/local/bin. /usr/local/bin because the Filesystem Hierarchy Standard (FHS) designates /usr/local as the location for locally installed software not managed by the system's package manager. Placing custom scripts in /usr/local/bin ensures they are in the default PATH for all users, while keeping them separate from system binaries in /usr/bin and /bin.

Answer

/var

Answer

/opt

Answer

/home

Question 13

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

Question 14

A database server with high I/O requirements needs a filesystem layout optimized for performance. The server has four identical 500GB SSDs. Which design best balances performance and reliability, considering the need to separate transaction logs from data files?

Accepted Answer

Use one SSD for transaction logs and the other three in RAID 0 for data files.. It isolates transaction logs on a dedicated SSD to eliminate write contention with data files, while the remaining three SSDs in RAID 0 maximize sequential throughput for data. This design prioritizes performance for high-I/O workloads, accepting the reliability trade-off of RAID 0 for data, which is acceptable when logs (critical for recovery) are on a separate, non-striped device.

Answer

Use all four SSDs in RAID 10.

Answer

Use two SSDs in RAID 1 for logs and two in RAID 1 for data.

Answer

Combine all four SSDs into a single RAID 0 volume, then partition for data and logs.

Question 15

An administrator needs to mount a USB drive with the ext4 filesystem automatically at boot. The drive has a filesystem label 'DATA'. Which entry in /etc/fstab will mount it at /mnt/data with noatime and default mount options?

Accepted Answer

LABEL=DATA /mnt/data ext4 noatime,defaults 0 0. It uses the filesystem label 'DATA' to identify the USB drive, which is more reliable than a device name like /dev/sdb1 that can change between boots. The mount options 'noatime,defaults' are specified in the correct order, with 'defaults' providing standard mount options (rw, suid, dev, exec, auto, nouser, async) and 'noatime' disabling access time updates to reduce writes. The entry also includes the proper ext4 filesystem type and the mount point /mnt/data.

Answer

/dev/sdb1 /mnt/data ext4 noatime,defaults 0 0

Answer

LABEL=DATA /mnt/data ext4 defaults 0 0

Answer

UUID=DATA /mnt/data ext4 noatime,defaults 0 0