Exam AWS Certified Solutions Architect - Professional topic 1 question 29 discussion

The question states “access **portions **of this data while the backups are taking place” meaning that in theory the whole data set does not need to stored on premise and can be streamed back from S3 on demand as required. A cached volume still presents the files as if they were present on the file system. Answer is A.

D . Stored volume keep all the data on site and can be mounted on site. All teh files are backed up to S3. It is a backup solution In cached only "portion of the data - cached" is kept on site and rest of the data lies on S3 It is a storage "extension" solution. If customer like to "backup" - It is likely that they want Stored volume, instead of cache

D is the correct one

A. Use Storage Gateway and configure it to use Gateway Cached volumes.

A. Use Storage Gateway and configure it to use Gateway Cached volumes. Short Explanation: AWS Storage Gateway: This service integrates on-premises environments with cloud storage for backups and data archiving. Gateway Cached Volumes: This configuration caches frequently accessed data on-premises while storing the entire dataset in the cloud. It presents a native file system interface and provides low-latency access to data, making it suitable for scenarios where users need to access data during backup processes. Block-based Storage: Storage Gateway supports block-based storage, which is necessary since your backup application requires POSIX-compatible block-based storage. Scalability and Cost Efficiency: Using Gateway Cached volumes allows for efficient use of on-premises storage, as only the most frequently accessed data is kept on-premises, while the bulk of the data is stored in AWS, reducing overall storage costs.

It's A. Storage Gateway with Gateway Cached volumes provides a virtual storage gateway that appears as a POSIX-compliant block device to your on-premises backup application. D - Gateway Stored Volumes are not directly POSIX-compatible.

I choose A, because it is said that Customer still wants to access portions of the data, so a cached volume will serve this requisite, better than a store one.

It says "Users must be able to access portions of this data" Answer is A not D

Since the use-case is calling for Backup to AWS, I chose D. Storage Gateway Stored volume is for a backup use-case to AWS. Whereas Cached volume use-case is to use AWS as primary storage platform which isn't mentioned in the question.

I vote A for 'to access portions of this data'

I also go with option A, not sure why the answer is given as D

Someone thinks 140T would be a problem for cached gateway. However, according to https://aws.amazon.com/storagegateway/faqs/?nc=sn&loc=6, "Each Volume Gateway can support up to 32 volumes. In cached mode, each volume can be up to 32 TB for a maximum of 1 PB of data per gateway (32 volumes, each 32 TB in size). In stored mode, each volume can be up to 16 TB for a maximum of 512 TB of data per gateway (32 volumes, each 16 TB in size)." If cached gateway can't handle 140T as a folder, neither can stored gateway.

I vote A for 'to access portions of this data'

POSIX-compatible block-based storage: volume Portion: Cached. Cached Volume.

"Backup should be mounted as single directory". This requirements suggests to use single volume? But max size of single storage gareway volume is 32TB.

D. In stored mode, each volume can be up to 16 TB for a maximum of 512 TB of data per gateway (32 volumes, each 16 TB in size) While cache mode only 16 TB

A.. coz Stored volumes make your entire data available locally on the gateway, while maintaining an asynchronous copy in the S3 bucket. This make entire copy avaliable for access. D is just a backup solution and keeping just a portion of data on-prem. This is not suitable for this use case.