- A
Amazon EBS with Multi-Attach enabled
Why wrong: Amazon EBS Multi-Attach allows a single EBS volume to be attached to up to 16 Nitro-based EC2 instances in the same Availability Zone. It does not support cross-AZ access, has limited scalability, and is not intended for petabyte-scale workloads. It is also not fully managed for scaling to petabytes.
- B
Amazon EFS
Amazon EFS provides a fully managed, elastic NFS file system that can be mounted on multiple EC2 instances across multiple Availability Zones. It scales automatically to petabytes, offers high durability, and is designed for concurrent access from thousands of instances. This matches all requirements.
- C
Amazon S3
Why wrong: Amazon S3 is an object storage service, not a file system. While it can be accessed from multiple instances, it does not provide a POSIX-compliant file system interface. Applications expecting a shared file system with standard file operations (like locking or appends) would not work directly with S3.
- D
Amazon EC2 Instance Store
Why wrong: Instance Store provides temporary block-level storage that is physically attached to the host computer. It is ephemeral (data is lost if the instance stops or terminates) and cannot be shared across multiple instances. It does not meet durability or shared access requirements.
CLF-C02 Cloud Technology and Services Practice Question
This CLF-C02 practice question tests your understanding of cloud technology and services. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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.
A company runs a web application on multiple Amazon EC2 instances across two Availability Zones. The application processes user-uploaded documents and must store them in a shared file system that all instances can access simultaneously. The file system must be scalable to petabytes, durable, and fully managed. Which AWS service should the company use to meet these requirements?
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
Amazon EFS
Amazon EFS is a fully managed, scalable, and durable NFS file system that can be mounted concurrently by multiple EC2 instances across different Availability Zones. It automatically scales storage capacity up to petabytes as files are added or removed, and it provides high durability by replicating data across multiple AZs within a region. This makes it the ideal choice for a shared file system that must be accessed simultaneously by all instances.
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.
- ✗
Amazon EBS with Multi-Attach enabled
Why it's wrong here
Amazon EBS Multi-Attach allows a single EBS volume to be attached to up to 16 Nitro-based EC2 instances in the same Availability Zone. It does not support cross-AZ access, has limited scalability, and is not intended for petabyte-scale workloads. It is also not fully managed for scaling to petabytes.
When this WOULD be correct
A question requiring a block storage volume attached to multiple EC2 instances in the same Availability Zone for a clustered database (e.g., Teradata) that needs low-latency, persistent storage with concurrent writes from a limited number of instances.
- ✓
Amazon EFS
Why this is correct
Amazon EFS provides a fully managed, elastic NFS file system that can be mounted on multiple EC2 instances across multiple Availability Zones. It scales automatically to petabytes, offers high durability, and is designed for concurrent access from thousands of instances. This matches all requirements.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Amazon S3
Why it's wrong here
Amazon S3 is an object storage service, not a file system. While it can be accessed from multiple instances, it does not provide a POSIX-compliant file system interface. Applications expecting a shared file system with standard file operations (like locking or appends) would not work directly with S3.
When this WOULD be correct
A company needs to store and serve static website assets (e.g., images, videos) with high durability and scalability, accessed via HTTP/HTTPS. The application does not require a file system mount; instead, it uses S3 APIs or SDKs to upload/download objects.
- ✗
Amazon EC2 Instance Store
Why it's wrong here
Instance Store provides temporary block-level storage that is physically attached to the host computer. It is ephemeral (data is lost if the instance stops or terminates) and cannot be shared across multiple instances. It does not meet durability or shared access requirements.
When this WOULD be correct
A question requiring high-performance, low-latency temporary storage for data that is replicated across instances, such as a cache or scratch space, where data loss is acceptable and persistence is not needed.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The CLF-C02 exam frequently reuses these exact scenarios with slightly different constraints.
✓Amazon EFSCorrect answer▾
Why this is correct
Amazon EFS provides a fully managed, elastic NFS file system that can be mounted on multiple EC2 instances across multiple Availability Zones. It scales automatically to petabytes, offers high durability, and is designed for concurrent access from thousands of instances. This matches all requirements.
✗Amazon EBS with Multi-Attach enabledWrong answer — click to see why▾
Why this is wrong here
Amazon EBS with Multi-Attach only supports up to 16 instances in a single Availability Zone, not across multiple AZs, and is limited to io1/io2 volumes, not scalable to petabytes or fully managed for shared file access.
★ When this WOULD be the correct answer
A question requiring a block storage volume attached to multiple EC2 instances in the same Availability Zone for a clustered database (e.g., Teradata) that needs low-latency, persistent storage with concurrent writes from a limited number of instances.
Why candidates choose this
Candidates may think Multi-Attach EBS provides a shared file system, but it is a block-level attachment with AZ and instance count limitations, not a scalable, fully managed file system like EFS.
✗Amazon S3Wrong answer — click to see why▾
Why this is wrong here
Amazon S3 is an object storage service, not a shared file system. It does not provide a POSIX-compliant file system interface that multiple EC2 instances can mount simultaneously for concurrent read/write access.
★ When this WOULD be the correct answer
A company needs to store and serve static website assets (e.g., images, videos) with high durability and scalability, accessed via HTTP/HTTPS. The application does not require a file system mount; instead, it uses S3 APIs or SDKs to upload/download objects.
Why candidates choose this
Candidates may confuse S3's scalability and durability with file system capabilities, overlooking the requirement for a shared file system mount (POSIX) that EFS provides.
✗Amazon EC2 Instance StoreWrong answer — click to see why▾
Why this is wrong here
Amazon EC2 Instance Store provides temporary block-level storage that is physically attached to the host computer, but data is lost when the instance is stopped or terminated, and it cannot be shared across multiple instances or Availability Zones.
★ When this WOULD be the correct answer
A question requiring high-performance, low-latency temporary storage for data that is replicated across instances, such as a cache or scratch space, where data loss is acceptable and persistence is not needed.
Why candidates choose this
Candidates may confuse instance store with persistent storage or assume it can be shared, overlooking its ephemeral nature and lack of multi-instance access.
Analysis generated from the official CLF-C02blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse Amazon S3's object storage capabilities with a shared file system, but S3 lacks POSIX file locking and mountability, making it unsuitable for simultaneous file-level access from multiple EC2 instances.
Detailed technical explanation
How to think about this question
Amazon EFS implements the NFSv4.1 protocol and uses a distributed data store that automatically replicates file data and metadata across multiple Availability Zones for high durability (99.999999999% annual durability). The file system scales performance based on the amount of data stored and the burst credit model, with throughput scaling from 50 MB/s per TB of storage in Bursting mode to provisioned throughput up to 10 GB/s. In real-world scenarios, EFS is commonly used for content management systems, web serving, and big data analytics where multiple instances need concurrent access to the same files.
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 media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.
Quick reference
AWS S3 Storage Class Comparison
| Storage Class | Min Duration | Retrieval | Use Case |
|---|---|---|---|
| S3 Standard | None | Immediate | Frequently accessed data |
| S3 Standard-IA | 30 days | Immediate | Infrequent access, rapid retrieval |
| S3 One Zone-IA | 30 days | Immediate | Non-critical infrequent data |
| S3 Intelligent-Tiering | None | Immediate–hours | Unknown or changing access patterns |
| S3 Glacier Instant | 90 days | Milliseconds | Archive with instant retrieval |
| S3 Glacier Flexible | 90 days | Minutes–hours | Archive, flexible retrieval |
| S3 Glacier Deep Archive | 180 days | Hours | Long-term compliance archive |
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.
- →
Cloud Technology and Services — study guide chapter
Learn the concepts, then practise the questions
- →
Cloud Technology and Services practice questions
Targeted practice on this topic area only
- →
All CLF-C02 questions
1,024 questions across all exam domains
- →
AWS Certified Cloud Practitioner CLF-C02 study guide
Full concept coverage aligned to exam objectives
- →
CLF-C02 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related CLF-C02 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Cloud Concepts practice questions
Practise CLF-C02 questions linked to Cloud Concepts.
Security and Compliance practice questions
Practise CLF-C02 questions linked to Security and Compliance.
Cloud Technology and Services practice questions
Practise CLF-C02 questions linked to Cloud Technology and Services.
Billing, Pricing, and Support practice questions
Practise CLF-C02 questions linked to Billing, Pricing, and Support.
AWS shared responsibility model practice questions
Practise CLF-C02 questions linked to AWS shared responsibility model.
AWS IAM practice questions
Practise CLF-C02 questions linked to AWS IAM.
AWS pricing practice questions
Practise CLF-C02 questions linked to AWS pricing.
AWS support plans practice questions
Practise CLF-C02 questions linked to AWS support plans.
AWS S3 practice questions
Practise CLF-C02 questions linked to AWS S3.
AWS EC2 practice questions
Practise CLF-C02 questions linked to AWS EC2.
Practice this exam
Start a free CLF-C02 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this CLF-C02 question test?
Cloud Technology and Services — This question tests Cloud Technology and Services — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Amazon EFS — Amazon EFS is a fully managed, scalable, and durable NFS file system that can be mounted concurrently by multiple EC2 instances across different Availability Zones. It automatically scales storage capacity up to petabytes as files are added or removed, and it provides high durability by replicating data across multiple AZs within a region. This makes it the ideal choice for a shared file system that must be accessed simultaneously by all instances.
What should I do if I get this CLF-C02 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 →
Keep practising
More CLF-C02 practice questions
- A company publishes a message each time a new product is added to its catalogue. Three services need to receive this mes…
- A media company stores frequently accessed video thumbnails in Amazon S3. The thumbnails are read multiple times every d…
- A company needs a service to translate domain names (like www.example.com) into IP addresses, check the health of their…
- A startup runs an application on AWS and receives a monthly bill that charges exactly for the number of compute hours us…
- A financial institution runs its core banking application on-premises due to regulatory requirements. It has connected i…
- A company wants to run a MySQL database in AWS without managing database software installation, applying patches, settin…
Last reviewed: Jun 11, 2026
This CLF-C02 practice question is part of Courseiva's free Amazon Web Services 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 CLF-C02 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.