Storage gateway is not used for storing content - only to transfer to the Cloud

There is no on-prem/non Aws infrastructure to create a gateway. Also, EFS+EBS is more expensive that EFS and S3. So D is the best option.

Amazon S3 provides low-cost object storage for storing large amounts of unstructured data like videos. The videos can be stored in S3 durably and reliably. For processing, the video files can be temporarily copied from S3 to an EBS volume attached to the EC2 instance. EBS provides low latency block storage for high performance video processing. Once processing is complete, the output can be stored back in S3.

D. Use Amazon S3 for storing the video content. Move the files temporarily over to an Amazon Elastic Block Store (Amazon EBS) volume attached to the server for processing. Amazon S3 (Simple Storage Service) is highly durable, scalable, and cost-effective for storing large volumes of data, such as video content. It offers lower storage costs compared to Amazon EFS and is suitable for storing large files like video content. For processing the video content, you can temporarily move the files from Amazon S3 to an Amazon EBS volume attached to the EC2 instances. This approach allows you to leverage the high-performance storage of Amazon EBS for processing, while still benefiting from the cost-effectiveness of Amazon S3 for long-term storage. Once processing is complete, you can remove the temporary files from the EBS volume and store the final results back in S3.

Selected Answer: A A would work, "Storage Gateway for files" can provide access to S3 (cheap) via NFS (what the clients are using now). It has some additional cost in addition to the S3 charges, but would still be way cheaper than EFS. B would work for a single server, but as it provides a volume via iSCSI, it could be mounted only to a single server - does not meet the 'multiple instances can access' requirement. C and D do not meet the 'multiple instances can access' requirement because EBS can't be easily attached to all servers at the same time.

Selected Answer: A AWS Storage Gateway S3 file gateway can be setup on EC2 ( https://repost.aws/knowledge-center/file-gateway-ec2 ). It use local disks/EBS for caching data. D: Can be used too, using attached EBS volume to each EC2 instance to process files. If require single EBS volume to be attached to multiple EC2, then it is possible too if they are in the same Availability Zone -> https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-volumes-multi.html. For me A and D both are possible, but expect AWS would like to select Storage GW

But how do you attach "an EBS volume" to all the servers, and how will you use the files on it then to serve customers.

A doesn't say "store content ON the gateway", it says "use AWS Storage Gateway for files" (which is the product) "to store the video content" [on S3].

Selected Answer: A I was initially going for D but EBS part makes no sense as it is not possible. Closest explanation of A is in this article: https://aws.amazon.com/blogs/storage/mounting-amazon-s3-to-an-amazon-ec2-instance-using-a-private-connection-to-s3-file-gateway/ A is missing a lot of key steps but D is just impossible. Maybe it's just the wording?

Selected Answer: A A is correct For D, how to move file from S3 to EBS temporarily????

Selected Answer: A Answer is closer to the following principle and D is near impossible to implement: "Amazon S3 File Gateway – Amazon S3 File Gateway supports a file interface into Amazon Simple Storage Service (Amazon S3) and combines a service and a virtual software appliance. By using this combination, you can store and retrieve objects in Amazon S3 using industry-standard file protocols such as Network File System (NFS) and Server Message Block (SMB). You deploy the gateway into your on-premises environment as a virtual machine (VM) running on VMware ESXi, Microsoft Hyper-V, or Linux Kernel-based Virtual Machine (KVM), or as a hardware appliance that you order from your preferred reseller. You can also deploy the Storage Gateway VM in VMware Cloud on AWS, or as an AMI in Amazon EC2. The gateway provides access to objects in S3 as files or file share mount points. With a S3 File Gateway, you can do the following"

Option D (S3 + EBS) is the most cost-effective and scalable choice for a service that involves storing video content and performing I/O-intensive transcoding for mobile platforms. Option A (S3 File Gateway) could work for applications with strict file system requirements but is less optimal for high-performance transcoding which is required by this online service

Cost effective = Use Amazon S3 for storing the video content. Move the files temporarily over to an Amazon Elastic Block Store (Amazon EBS) volume attached to the server for processing

Answer D is correct. Storage gateway is not used for storing content - only to transfer to the Cloud

And even if ignoring the 'multiple instances can access' requirement, D would be against WAF; for temporary storage you'd use instance storage, not EBS.

The question doesn't give enough information. Well, quite a few AWS exam questions don't provide enough info. Ideally, A could be the best answer if it mentions S3 as the backend of storage gateway. Because if it doesn't mention S3 as the backend, that implies either Storage gateway as the storage(which is impossible) or continue using EFS(also impossible). D is not ideal, because it will introduce video download cost for downloading files from S3 to EBS temporary storage. But it is the best option we have.

EFS is already used, why EBS is an option in the answer?

But how do you attach "an EBS volume" to all the servers, and how will you use the files on it then to serve customers? A doesn't say "store content ON the gateway", it says "use AWS Storage Gateway for files" (which is the product) "to store the video content" [on S3]. And to be exact, Storage Gateway is not "to transfer to the cloud" but to provide access to S3 storage via SMB or NFS.

I like this answer below -- A

Answer A is closer to the following principle and D is near impossible to implement: "

A mentions "AWS Storage Gateway for files" which implies S3 as the backend storage. D does not meet the 'multiple instances can access for processing' requirement.

I agree. This documentation has convinced me. https://docs.aws.amazon.com/filegateway/latest/files3/what-is-file-s3.html

Storage gateway is intended for on-premises applications to access cloud storage, so A, B is out. The question explicitly states that the files are uploaded and stored in EFS, not S3, so D is not correct. The answer is C. The EFS storage costs 10 times more than EBS, so moving files to EBS after processing is the solution.

We are ditching EFS in favor of S3. So there is no longer simultaneous access happening. Whoever needs the file, downloads it from S3, process it on their EC2 instance and save it back to S3.

AWS Storage Gateway is a hybrid cloud storage service that connects on-premises environments with AWS cloud storage

Creating storage gateway for Files will mount S3 bucket as an NFS volume that can be shared among EC2 Instances in the same manner as EFS but more cost effectively.