AWS Certified Solutions Architect – Associate (SAA-C03) — Question 804

A company runs its applications on Amazon EC2 instances that are backed by Amazon Elastic Block Store (Amazon EBS). The EC2 instances run the most recent Amazon Linux release. The applications are experiencing availability issues when the company's employees store and retrieve files that are 25 GB or larger. The company needs a solution that does not require the company to transfer files between EC2 instances. The files must be available across many EC2 instances and across multiple Availability Zones.

Which solution will meet these requirements?

Answer options

• A. Migrate all the files to an Amazon S3 bucket. Instruct the employees to access the files from the S3 bucket.
• B. Take a snapshot of the existing EBS volume. Mount the snapshot as an EBS volume across the EC2 instances. Instruct the employees to access the files from the EC2 instances.
• C. Mount an Amazon Elastic File System (Amazon EFS) file system across all the EC2 instances. Instruct the employees to access the files from the EC2 instances.
• D. Create an Amazon Machine Image (AMI) from the EC2 instances. Configure new EC2 instances from the AMI that use an instance store volume. Instruct the employees to access the files from the EC2 instances.

Correct answer: C

Explanation

Amazon Elastic File System (Amazon EFS) is designed to provide shared, concurrent file system access to multiple Amazon EC2 instances spanning multiple Availability Zones. Amazon EBS volumes cannot be attached to multiple instances across different Availability Zones simultaneously, making Option B incorrect. Amazon S3 (Option A) would require rewriting the application to use API calls instead of a standard file system interface, and instance store volumes (Option D) are ephemeral and confined to a single physical host.