LPIC-1 Devices, Filesystems and FHS Practice Question
Exhibit
# /etc/fstab /dev/sda1 /boot ext4 defaults 1 2 /dev/sda2 / ext4 defaults 0 1 /dev/sda3 /home ext4 defaults 0 2 192.168.1.100:/export /mnt/nfs nfs defaults,_netdev 0 0 # mount -a output: mount: /mnt/nfs: can't read superblock
Refer to the exhibit. The 'mount -a' command fails for the NFS mount. What is the most likely cause?
⚠ Common exam trap
LPI exams frequently test the distinction between local mount point existence and network service availability, tricking candidates into thinking a missing mount point is the cause when the real issue is server-side or network connectivity.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The NFS server is not exporting the directory or is unreachable.
The 'mount -a' command reads /etc/fstab and attempts to mount all entries. For an NFS mount, the most common failure is that the NFS server is not exporting the specified directory or is unreachable, which causes the mount to fail with an error like 'mount.nfs: access denied by server while mounting' or 'mount.nfs: No route to host'. This is the correct answer because network-based filesystem mounts depend on server availability and export configuration.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The local mount point /mnt/nfs does not exist.
Why it's wrong here
A missing local mount point produces a distinct error, yet the exhibit typically shows the NFS-specific failure rather than a directory-not-found message. This option tempts because absent mount points genuinely break 'mount -a', but that occurs when /etc/fstab references a path never created, not in the exhibited NFS timeout or server-unreachable case.
- ✗
The filesystem type 'nfs' is not supported by the kernel.
Why it's wrong here
The kernel almost certainly includes NFS client support; the exhibit would show a different error if the module were absent. This option is tempting because missing kernel modules do break mounts, but that scenario arises with custom-compiled kernels, not standard distributions where nfs.ko ships by default.
- ✓
The NFS server is not exporting the directory or is unreachable.
Why this is correct
The mount fails because the client cannot reach the server or the export is absent; 'mount -a' relies on the server's export list and network reachability. Neither /etc/fstab syntax nor local mount options cause this, so an unexported or unreachable NFS server is the likely cause.
- ✗
The 'defaults' option is missing for the NFS entry.
Why it's wrong here
Omitting 'defaults' does not prevent mounting; mount applies implicit defaults when no options are listed. This option tempts because 'defaults' appears in most fstab entries, but its absence only matters when specific flags like 'noauto' or 'ro' are required, not for a basic NFS mount failure.
Go deeper
Related to this question
About these practice questions
This LPIC-1 question is part of Courseiva's 402-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This LPIC-1 practice question is part of Courseiva's free LPI certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the LPIC-1 exam.