In which scenario is using Amazon EBS preferred over Amazon EFS?

Using Amazon EBS is preferred when low-latency and high-performance storage is needed for an individual EC2 instance because EBS volumes are specifically designed to provide block storage that is tightly coupled with EC2 instances. They offer high IOPS (Input/Output Operations Per Second) and low-latency access, making them suitable for workloads that require swift read and write operations, such as databases or performance-sensitive applications.

EBS volumes are only accessible from the instance to which they are attached, which ensures that performance is optimized for that specific instance. This level of performance is critical in scenarios such as high-transaction databases where consistent and scalable storage and quick response times are necessary.

In contrast, the other options target scenarios where Amazon EFS would be more suitable. For instance, if shared storage access across multiple instances is necessary, Amazon EFS excels in providing a fully managed file storage service that can be accessed concurrently from multiple EC2 instances. Similarly, EFS is designed to scale storage dynamically, making it a preferred choice for applications that require flexibility in capacity as data grows. Lastly, for content repositories that need to serve multiple applications, EFS provides the capability for applications to share files seamlessly and concurrently, thus optimizing workflow and collaboration.