Exam AWS Certified SysOps Administrator - Associate topic 1 question 158 discussion

Stored volumes make your entire data available locally on the gateway, while maintaining an asynchronous copy in the S3 bucket. Cached volumes store the full volume in the S3 bucket, while only keeping the recently used data in local cache.

The answer is D. A, B are clearly not suitable. In terms of C vs D, the questions states "All of the data must be available locally" When a volume gateway works in cached mode it only stores the frequently accessed data locally for low-latency access, not the entire dataset. On the other hand, with stored volume gateway you backup all your data locally.

data available on local-> stored volume

Volume Gateway provides an iSCSI target, which enables you to create block storage volumes and mount them as iSCSI devices from your on-premises or EC2 application servers. The Volume Gateway runs in either a cached or stored mode. In the cached mode, your primary data is written to S3, while retaining your frequently accessed data locally in a cache for low-latency access. In the stored mode, your primary data is stored locally and your entire dataset is available for low-latency access while asynchronously backed up to AWS.

C. Use AWS Storage Gateway, and configure it to use gateway-cached volumes. AWS Storage Gateway is a service that connects an on-premises data center to the cloud. It provides block-based storage that is compatible with the Portable Operating System Interface (POSIX) and can be used as a target for data backups. Gateway-cached volumes allow you to store your data locally, while asynchronously backing up that data to Amazon S3. This allows you to retain local access to your data, while still providing the benefits of cloud-based data storage and backup.

dddddd

https://docs.amazonaws.cn/en_us/storagegateway/latest/vgw/StorageGatewayConcepts.html By using stored volumes, you can store your primary data locally, while asynchronously backing up that data to Amazon. Stored volumes provide your on-premises applications with low-latency access to their entire datasets. At the same time, they provide durable, offsite backups.

Ans: D With Volume Stored Gateway all your data stays onprem and backups are sent to S3 as EBS snapshots. It's also POSIX compatible