CLF-C02 Cloud Technology and Services Practice Question
A media processing company runs multiple Amazon EC2 instances in different Availability Zones. All instances need to read and write to a shared file system simultaneously. The file system must be fully managed, automatically replicated across multiple Availability Zones for durability, and accessible by all instances using standard file access protocols. The company does not want to provision or manage any file servers. Which AWS service should the company use to meet these requirements?
⚠ Common exam trap
Test-takers frequently confuse Amazon EBS Multi-Attach (Option B) as a solution for shared storage across AZs, but it is strictly limited to a single AZ and requires Nitro-based instances, making it unsuitable for multi-AZ access.
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 (Elastic File System) is a fully managed, scalable NFS file system that can be mounted concurrently by multiple EC2 instances across different Availability Zones. It automatically replicates data across multiple AZs for durability and uses standard NFSv4.1 and NFSv4.0 protocols, meeting all requirements without any server provisioning or management.
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 S3
Why it's wrong here
Incorrect. Amazon S3 is an object storage service, not a file system. It does not support concurrent file-level locking or standard file access protocols like NFS or SMB needed for simultaneous read/write from multiple EC2 instances.
When this WOULD be correct
A company needs to store and retrieve any amount of data from anywhere (e.g., web applications, data lakes, backups) with high durability and scalability, and does not require a file system interface. The data is accessed via HTTP/HTTPS APIs, not standard file protocols.
- ✗
Amazon EBS Multi-Attach
Why it's wrong here
Incorrect. Amazon EBS Multi-Attach allows a single EBS volume to be attached to up to 16 EC2 instances, but all instances must be in the same Availability Zone. It does not work across Availability Zones, so it cannot meet the requirement for high availability across zones.
When this WOULD be correct
An exam question requiring a block-level storage volume that can be attached to multiple EC2 instances in the same Availability Zone for high availability, where the instances need low-latency access to shared data and the volume is provisioned and managed by the user.
- ✓
Amazon EFS
Why this is correct
Correct. Amazon EFS provides a fully managed, elastic NFS file system that can be mounted on multiple EC2 instances across different Availability Zones simultaneously. It automatically replicates data across zones within a region for durability and is ideal for shared file storage.
- ✗
Amazon FSx for Windows File Server
Why it's wrong here
Incorrect. Amazon FSx for Windows File Server is a fully managed Windows file system that supports the SMB protocol. While it can be accessed from multiple instances, it is designed for Windows-based workloads. For a general, Linux-friendly shared file system that does not require licensing overhead, Amazon EFS is a better fit.
When this WOULD be correct
A company needs a fully managed Windows-based file system that supports SMB protocol and integrates with Active Directory, and they are willing to configure multi-AZ deployment manually. For example, a Windows application requiring shared file storage with Windows-native features.
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
Correct. Amazon EFS provides a fully managed, elastic NFS file system that can be mounted on multiple EC2 instances across different Availability Zones simultaneously. It automatically replicates data across zones within a region for durability and is ideal for shared file storage.
✗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 support standard file access protocols like NFS or SMB, and it cannot be mounted as a file system by EC2 instances for simultaneous read/write access.
★ When this WOULD be the correct answer
A company needs to store and retrieve any amount of data from anywhere (e.g., web applications, data lakes, backups) with high durability and scalability, and does not require a file system interface. The data is accessed via HTTP/HTTPS APIs, not standard file protocols.
Why candidates choose this
Candidates may confuse S3's high durability and availability with file system capabilities, or think that S3's object storage can be used as a shared file system via third-party tools, but the question explicitly requires standard file access protocols and a fully managed file system.
✗Amazon EBS Multi-AttachWrong answer — click to see why▾
Why this is wrong here
Amazon EBS Multi-Attach allows attaching a single EBS volume to multiple EC2 instances, but it is limited to a single Availability Zone and does not provide automatic replication across multiple AZs or a shared file system with standard file access protocols.
★ When this WOULD be the correct answer
An exam question requiring a block-level storage volume that can be attached to multiple EC2 instances in the same Availability Zone for high availability, where the instances need low-latency access to shared data and the volume is provisioned and managed by the user.
Why candidates choose this
Candidates may confuse 'shared file system' with 'shared block storage' and think Multi-Attach provides similar functionality, overlooking the multi-AZ replication and managed file system requirements.
✗Amazon FSx for Windows File ServerWrong answer — click to see why▾
Why this is wrong here
Amazon FSx for Windows File Server is not fully managed in terms of automatic replication across multiple Availability Zones; it requires manual configuration for multi-AZ deployment and does not natively support automatic replication across AZs for durability as required.
★ When this WOULD be the correct answer
A company needs a fully managed Windows-based file system that supports SMB protocol and integrates with Active Directory, and they are willing to configure multi-AZ deployment manually. For example, a Windows application requiring shared file storage with Windows-native features.
Why candidates choose this
Candidates may confuse FSx for Windows File Server with a fully managed file system that supports multi-AZ, but they overlook that EFS is the only option that provides automatic replication across AZs without manual setup.
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?”
Go deeper
Related to this question
About these practice questions
Courseiva writes every CLF-C02 question from scratch — 988 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or 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 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.