CLF-C02 Cloud Technology and Services Practice Question

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

  Amazon S3 is an object storage service that stores data as objects in buckets and exposes it via REST APIs, not as a POSIX-compliant file system. It cannot be directly mounted by EC2 instances as a shared, multi-AZ file system, and it lacks native file-system semantics such as locking, directories, or byte-range file updates. While tools like S3FS-FUSE can attempt to mount S3 as a file system, they are not a native AWS offering and do not deliver the performance or consistency of EFS for general-purpose file workloads. Therefore, S3 fails the requirement for a file system that can be mounted by multiple EC2 instances across Availability Zones.

  When this WOULD be correct

  A company needs to store and retrieve any amount of data from anywhere (e.g., backup, static website hosting, or data lake) with high durability and scalability, and does not require a file system mount or concurrent file-level access from EC2 instances.

• ✗

  Amazon EBS

  Why it's wrong here

  Amazon EBS provides block storage volumes. A standard EBS volume can be attached to only one EC2 instance at a time, and multi-attach EBS is limited to certain instance types and requires a clustered file system. Additionally, EBS does not automatically scale capacity.

  When this WOULD be correct

  A question requiring a single EC2 instance to have persistent, high-performance block storage for a database, with snapshots for backup and the ability to change volume type without stopping the instance (e.g., using EBS Multi-Attach for a limited number of instances in the same AZ).

• ✓

  Amazon EFS

  Why this is correct

  Amazon EFS provides a fully managed, scalable NFS file system that can be mounted by multiple EC2 instances across different Availability Zones. It automatically scales storage capacity on demand and charges only for the storage used, meeting all the stated requirements.

• ✗

  Amazon FSx for Windows File Server

  Why it's wrong here

  Amazon FSx for Windows File Server requires provisioning storage capacity in advance and does not support automatic growth and shrinkage as files are added or removed, failing the requirement to avoid upfront capacity planning. It is tempting because it provides a shared file system mountable by multiple EC2 instances across Availability Zones, and would be correct if the application required native Windows file-sharing protocols such as SMB or integration with Microsoft Entra ID.

  When this WOULD be correct

  A company needs a shared file system for Windows-based EC2 instances that supports SMB protocol, Active Directory integration, and requires high availability across multiple Availability Zones. The company is willing to provision storage capacity upfront and does not need automatic scaling.

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.

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?”