The correct answer includes the statement that /var/tmp is used for temporary storage, as this directory holds transient files like logs, crash data, and core dumps that are cleared upon reboot. This is a fundamental distinction on the Junos file system because /config stores the active and backup configuration files—juniper.conf and juniper.conf.gz—which are critical for device boot and operation, while /var/tmp is explicitly non-persistent. On the JNCIA-Junos exam, this question tests your ability to differentiate between persistent and volatile directories, often appearing as a “choose two” trap where candidates confuse /var/tmp with /config or /var/log. A common memory tip is to think of “tmp” as “temporary” and “config” as “committed”—if it survives a reboot, it belongs in /config; if it vanishes, it belongs in /var/tmp.
JNCIA-JUNOS Junos OS Fundamentals Practice Question
This JNCIA-JUNOS practice question tests your understanding of junos os fundamentals. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Which TWO statements are true about the Junos file system? (Choose two.)
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The /config directory contains configuration files.
Option A is correct because the /config directory in the Junos file system stores the active and backup configuration files, including juniper.conf and juniper.conf.gz. These files are critical for device operation and are loaded during the boot process.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
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 /config directory contains configuration files.
Why this is correct
/config stores the active and candidate configuration files.
Related concept
Read the scenario before looking for a memorised answer.
✓
The /var/tmp directory is used for temporary storage.
Why this is correct
/var/tmp is a temporary filesystem.
Related concept
Read the scenario before looking for a memorised answer.
✗
The /altroot directory is a backup root filesystem.
Why it's wrong here
There is no standard /altroot directory; backup root is /altroot on some systems but not common Junos.
✗
The /kernel directory contains the operating system kernel.
Why it's wrong here
The kernel is loaded from /boot, not a /kernel directory.
✗
The root directory (/) is a RAM disk.
Why it's wrong here
The root filesystem is stored on flash, not a RAM disk.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates may confuse the /altroot directory with a backup root filesystem, when in fact it is used for alternate root images during software upgrades, not a persistent backup.
Detailed technical explanation
How to think about this question
The Junos file system is organized into standard Unix-like directories, but with Juniper-specific additions. The /config directory is critical for configuration management, and the /var/tmp directory is used for temporary files such as log files during troubleshooting or software downloads. Understanding the filesystem layout is essential for tasks like recovering from a corrupted configuration or managing storage during upgrades.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the JNCIA-JUNOS exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Junos OS Fundamentals — This question tests Junos OS Fundamentals — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The /config directory contains configuration files. — Option A is correct because the /config directory in the Junos file system stores the active and backup configuration files, including juniper.conf and juniper.conf.gz. These files are critical for device operation and are loaded during the boot process.
What should I do if I get this JNCIA-JUNOS question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. Which THREE statements about the Junos OS file system are true? (Choose three.)
hard
A.The /etc directory contains all log files
B.The /altroot directory is used for user-uploaded files
✓ C.The active configuration is stored in the /config directory
✓ D.Log files are typically stored in /var/log
✓ E.The file system is UNIX-like with directories such as /, /var, /config
Why C: Option C is correct because the active configuration in Junos OS is stored as a file named `junos.conf` in the `/config` directory. This file is used by the system to load the running configuration at boot time, and it is distinct from the candidate configuration stored in `/var/db/config`.
Last reviewed: Jun 24, 2026
Question Discussion
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This JNCIA-JUNOS practice question is part of Courseiva's free Juniper Networks 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 JNCIA-JUNOS exam.
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