Amazon Storage Gateway - In Detail

AWS Storage Gateway; is a service that connects an on-premises software appliance with cloud-based storage to provide seemless and secure integration between an organizations on-premise IT environment and AWS's storage infrastructure. The service enables you to securely store data to the AWS cloud for scalable and cost-efficient storage.

Files are stored as objects in your S3 buckets, accessed through a Network File System (NFS) mount point. Ownership, permissions, and timestamps are durably stored in S3 in the user-metadata of the object associated with the file. Once objects are transferred to S3, they can be managed as native S3 objects, and bucket policies such as versioning, lifecycle management and cross-region replication apply directly to the objects stored in the bucket.

Storage Gateway is a virtual appliance installed into a host in the data center and this will propagate replicate data to AWS (particularly to S3/Galcier). This is available for download as a virtual machine image.

Once the Gateway is installed and associated with the AWS account through the activation process, you can use the AWS management console to create the storage gateway option that is right for you.

Four types of Storage Gateways:

1. File Gateway (NFS) used for storing flat files on S3.

1. Volume Gateway (iSCSI) used for block based storage.
   - Stored Volumes: Entire copy of data on premis.
   - Cached Volumes: Storing most recently accessed data.
2. Tape Gateway (VTL)