LPIC-1 Devices, Filesystems and FHS Practice Test 6 — 15 Questions

Question 1

A system administrator needs to check if a filesystem has any errors without actually performing a repair. Which command should be used?

Accepted Answer

fsck -n /dev/sdb1. The `-n` option with `fsck` performs a read-only check, displaying any filesystem errors without making any modifications or repairs. This is the correct choice for a non-destructive check that only reports issues.

Answer

fsck -y /dev/sdb1

Answer

fsck -N /dev/sdb1

Answer

e2fsck -p /dev/sdb1

Question 2

Which of the following directories is NOT defined in the Filesystem Hierarchy Standard (FHS)?

Accepted Answer

/net. The /net directory is not defined in the Filesystem Hierarchy Standard (FHS). The FHS specifies standard directory locations like /run, /proc, /media, and /sys, but /net is not a required or standard directory; it may appear in some systems as a mount point for network filesystems but is not part of the FHS specification.

Answer

/run

Answer

/proc

Answer

/media

Answer

/sys

Question 3

A Linux system has multiple disk partitions. The administrator wants to view the UUID of a specific partition for use in /etc/fstab. Which command will display the UUID?

Accepted Answer

blkid /dev/sda1. The `blkid` command queries the libblkid library to display block device attributes, including the UUID and filesystem type. Running `blkid /dev/sda1` outputs the UUID for that specific partition, which can be directly copied into /etc/fstab for persistent mounting.

Answer

fdisk -l /dev/sda1

Answer

lsblk -f

Answer

cat /proc/partitions

Question 4

A company is setting up a database server that requires high reliability and support for snapshots. The storage will be on a single large disk. Which filesystem is best suited for this requirement?

Accepted Answer

btrfs. Btrfs (B-tree filesystem) is best suited for this requirement because it natively supports snapshots, checksumming, and copy-on-write (CoW) for high reliability, all on a single disk. Unlike other Linux filesystems, btrfs provides built-in snapshot and rollback capabilities without requiring an external volume manager, making it ideal for database servers needing consistent point-in-time backups.

Answer

ext4

Answer

NTFS

Answer

XFS

Question 5

After modifying /etc/fstab, an administrator wants to test if the new mount points can be mounted without rebooting. Which command should be used?

Accepted Answer

mount -a. The `mount -a` command reads /etc/fstab and mounts all filesystems listed there that are not already mounted, making it the correct way to test new entries without rebooting. This command respects the mount options and order defined in fstab, allowing the administrator to verify that the new mount points work correctly.

Answer

systemctl daemon-reload

Answer

mount -o remount

Answer

mount -t ext4

Question 6

A user complains that a filesystem is reporting 'Disk quota exceeded' even though the user has not stored any new files recently. What could be the cause?

Accepted Answer

The user has exceeded the inode quota. Linux filesystems enforce two types of quotas: block quotas (for disk space) and inode quotas (for the number of files and directories). If the user has not stored new files recently but still receives a 'Disk quota exceeded' error, it is likely that they have exceeded their inode quota, meaning they have created too many files or directories (each consuming an inode), even if those files are small or empty. The error message is generic and can refer to either quota type, so the inode limit is the probable cause when no recent data writes have occurred.

Answer

Symlinks are counted against the quota

Answer

Hard links are consuming additional inodes

Answer

File ownership is misconfigured

Question 7

An administrator runs `fsck /dev/sdb1` on an ext4 filesystem that is currently mounted. What is the likely outcome?

Accepted Answer

It will refuse and exit with a warning. Running fsck on a mounted ext4 filesystem is unsafe because the kernel may have cached metadata that differs from the on-disk state, leading to false corruption detection or actual data loss. The fsck tool detects the mounted state via /proc/mounts or the kernel's internal mount table and refuses to run, printing a warning and exiting with a non-zero exit code (typically 8). This is a deliberate safety mechanism to prevent filesystem corruption.

Answer

It will succeed and repair any errors

Answer

It will automatically remount the filesystem read-only and check

Answer

It will safely perform a read-only check

Question 8

Which TWO of the following commands can be used to create a new filesystem on a partition?

Accepted Answer

mkfs.ext4. B is correct because `mkfs.ext4` is a specific command that creates an ext4 filesystem on a partition. E is correct because `mkfs` is a generic front-end that can create various filesystem types (e.g., ext4, xfs, btrfs) based on the `-t` option or by invoking filesystem-specific wrappers like `mkfs.ext4`.

Answer

fdisk

Answer

parted

Answer

fsck

Question 9

Which THREE of the following directories are defined in the Filesystem Hierarchy Standard (FHS) and are expected to exist on a typical Linux system?

Accepted Answer

/run. B is correct because /run is a tmpfs directory defined in FHS 3.0+ that stores volatile runtime data (e.g., PID files, Unix sockets) since boot. It replaced /var/run to ensure early-boot processes have a writable location before /var is mounted.

Answer

/net

Answer

/opt

Question 10

Refer to the exhibit. Based on the mount options shown, which filesystem is most likely to store filenames with mixed case and support long filenames?

Accepted Answer

/dev/sdc1. The mount options shown for /dev/sdc1 include 'utf8' and 'codepage=437', which are characteristic of VFAT (or FAT32) filesystems. VFAT supports mixed-case filenames (though it is case-insensitive) and long filenames via the VFAT extension, which stores up to 255 UTF-16 characters. The other filesystems are either ext4 (which also supports mixed case and long names but does not use codepage/utf8 options) or tmpfs (which is RAM-based and not typically mounted with such options).

Answer

/dev/sda2

Answer

/dev/sda1

Answer

/dev/sdb1

Answer

tmpfs

Question 11

Refer to the exhibit. An administrator attempts to remount /mnt as read-only but receives the error shown. What is the most likely cause?

Accepted Answer

The /mnt directory is not a mount point. The error 'mount: /mnt is not a mount point' indicates that the administrator attempted to use the `remount` option on a directory that is not currently a mount point. The `mount -o remount` command only works on directories where a filesystem is already mounted; it modifies the mount options of an existing mount, not a regular directory. Since /mnt is not a mount point, the kernel rejects the operation with this specific error.

Answer

The /mnt directory is not empty

Answer

The /mnt directory does not exist

Answer

The filesystem is already mounted read-only

Question 12

A medium-sized company runs a web server on Linux with two 1TB disks in a software RAID1 (mdadm) configuration for the root filesystem and /var. Recently, the /var partition is reporting low disk space. The administrator discovers that old log files are consuming space but should be rotated. However, the logrotate service is not running. After starting logrotate, it fails to rotate some logs because of missing directories. Additionally, the administrator wants to add a third disk (500GB SSD) for additional storage and mount it under /srv/webdata. The disk is new and not partitioned. The server uses systemd and the current /etc/fstab uses UUIDs. What is the correct sequence of steps to add the new disk and ensure it is mounted automatically at boot?

Accepted Answer

Partition the disk with fdisk, create an ext4 filesystem, create the mount point, mount the filesystem, obtain the UUID, add an entry to /etc/fstab using the UUID, and run mount -a to verify.. It follows the standard procedure for adding a new disk to a Linux system: partition the disk (even if only one partition is needed), create a filesystem, create a mount point, mount it, obtain the UUID (e.g., via blkid), add an entry to /etc/fstab using the UUID for reliable boot-time mounting, and verify with mount -a. This ensures the disk is mounted automatically at boot, independent of device name changes, and aligns with systemd's expectation of UUID-based fstab entries.

Answer

Format the disk with ext4, add an entry to /etc/fstab using the device path /dev/sdc with the nofail option, then mount -a.

Answer

Add the disk to the existing RAID1 array to expand it, then grow the filesystem to use the new space.

Answer

Initialize the disk as an LVM physical volume, extend the existing volume group, create a logical volume, format it, mount it, and add to /etc/fstab.

Question 13

A system administrator notices that a server with an ext4 filesystem fails to boot after editing /etc/fstab. The error message indicates that the root filesystem cannot be mounted. Which of the following is the most likely cause?

Accepted Answer

The UUID or device name for the root filesystem is incorrect.. If the UUID or device name for the root filesystem in /etc/fstab is incorrect, the kernel cannot locate the root device during boot, resulting in a mount failure. The init process reads /etc/fstab to mount the root filesystem, and any mismatch—such as a typo in the UUID or a stale device path—will cause the system to drop into emergency mode.

Answer

The root filesystem is mounted read-only.

Answer

The swap partition entry is missing.

Answer

The filesystem type is specified as 'auto' instead of 'ext4'.

Question 14

A company wants to migrate a database server from ext4 to XFS to support larger files and better scalability. The current data resides on a single partition /dev/sda1 mounted at /data. Which procedure ensures a successful migration with minimal downtime?

Accepted Answer

Add a new disk, create a partition with mkfs.xfs, mount it at /mnt, copy /data contents using cp -a, update /etc/fstab to use the new device, and remount.. It provides a safe, low-downtime migration path: create a new XFS filesystem on a separate disk, copy the existing data with `cp -a` to preserve permissions and metadata, update `/etc/fstab` to mount the new XFS device at `/data`, and remount. This avoids modifying the original ext4 partition and ensures the database files are intact on a supported filesystem.

Answer

Use dd if=/dev/sda1 of=/dev/sdb1 bs=4M to clone the partition, then change fstab to use /dev/sdb1.

Answer

Run tune2fs -O xfs /dev/sda1 to change the filesystem type.

Answer

Mount an NFS share, use rsync to copy data to the NFS mount, then unmount and reformat the original partition with XFS.

Question 15

A system administrator needs to locate the largest directories under /var to free up disk space. Which command is most appropriate?

Accepted Answer

du -sk /var/* | sort -rn. `du -sk /var/* | sort -rn` calculates the disk usage in kilobytes for each top-level item under /var, then sorts them numerically in reverse order, showing the largest directories first. This directly addresses the need to locate the largest directories to free up space, as `du` reports actual disk usage (including subdirectories) rather than file sizes.

Answer

df -h /var

Answer

find /var -size +100M

Answer

ls -lS /var