AWS Storage Gateway

AWS Storage Gateway connects an on-premises software appliance with cloud-based storage to provide seamless integration with data security features between your on-premises IT environment and the AWS storage infrastructure.

There are three types of Storage Gateways provided by AWS:


File Gateway: The gateway provides access to objects in S3 as files or file share mount points. 

• VM Image for the gateway needs to be installed and activated. EC2 AMI is also available.
• Create and configure your file share and associate that share with your Amazon S3 bucket so that it is accessible by clients using either the NFS or SMB protocol.
• Files written to a file share become objects in Amazon S3, with the path as the key. There is a one-to-one mapping between files and objects, and the gateway asynchronously updates the objects in Amazon S3 as you change the files. 
• Existing objects in the bucket appear as files in the file system, and the key becomes the path.
• Objects are encrypted with with Amazon S3–server-side encryption keys (SSE-S3). All data transfer is done through HTTPS.
• The service optimizes data transfer between the gateway and AWS using multipart parallel uploads or byte-range downloads, to better use the available bandwidth.
• Local cache is maintained to provide low latency access to the recently accessed data and reduce data egress charges.

Cached Volume Gateway: 

• Amazon S3 as your primary data storage.
• frequently accessed data locally in your storage gateway
• You can create storage volumes up to 32 TiB in size and attach to them as iSCSI devices from your on-premises application servers.
• Each gateway configured for cached volumes can support up to 32 volumes for a total maximum storage volume of 1,024 TiB (1 PiB).

                                         

You also allocate disks on-premises for the VM.

• Disks for use by the gateway as cache storage
• Disks for use by the gateway as the upload buffer – To prepare for upload to Amazon S3, your gateway also stores incoming data in a staging area, referred to as an upload buffer.

You can take incremental backups, called snapshots, of your storage volumes in Amazon S3. These point-in-time snapshots are also stored in Amazon S3 as Amazon EBS snapshots. You can initiate snapshots on a scheduled or one-time basis.

All gateway data and snapshot data for cached volumes is stored in Amazon S3 and encrypted at rest using server-side encryption (SSE).

Stored Volume Gateway: 

You also allocate disks on-premises for the VM.

• you can store your primary data locally, while asynchronously backing up that data to AWS.
• data is asynchronously backed up to Amazon S3 as Amazon Elastic Block Store (Amazon EBS) snapshots.
• Stored volumes can range from 1 GiB to 16 TiB in size and must be rounded to the nearest GiB. Each gateway configured for stored volumes can support up to 32 volumes and a total volume storage of 512 TiB (0.5 PiB).

                                            

Tape Gateway: 
Refer Snowball.