AWS Storage Gateway

The Three Types of Storage Gateways

AWS Storage Gateway offers three different types of gateways to connect your applications to AWS storage, each designed for a specific use case and interface protocol.

| Gateway Type | Interface Protocol | Primary Use Case | Cloud Storage Backend |

| :--- | :--- | :--- | :--- |

| File Gateway | NFS & SMB | On-premises file shares, migrating file data, cloud-native file access. | Amazon S3 |

| Volume Gateway | iSCSI | Block storage for applications (databases, VM volumes), backup and disaster recovery. | Amazon S3 (as EBS Snapshots) |

| Tape Gateway | VTL (iSCSI) | Replacing physical tape libraries with a cloud-based virtual tape library. | Amazon S3, S3 Glacier, S3 Glacier Deep Archive |

1. File Gateway (NFS & SMB)

File Gateway provides a seamless way to connect to Amazon S3 for file-based applications.

• How it Works: It presents a standard file share using the Network File System (NFS) or Server Message Block (SMB) protocol. When your application writes files to this share, the File Gateway converts them into objects in your specified S3 bucket.

• 1:1 Object Mapping: Each file written to the gateway becomes a single object in S3, making your data natively accessible in the cloud for services like Amazon Athena, Amazon Redshift Spectrum, or S3 batch operations.

• Local Cache: The gateway maintains a local cache of recently accessed data, providing low-latency access for your most active files.

• Use Cases:

  • Storing on-premises file data (like documents, images, and videos) in S3.

  • Migrating on-premises file-based application data to AWS without modification.

  • Backing up on-premises databases (like SQL Server or Oracle) directly to file shares that store the data in S3.

2. Volume Gateway (iSCSI)

Volume Gateway provides cloud-backed block storage volumes to your on-premises applications using the iSCSI protocol. It has two distinct modes of operation.

Cached Volumes Mode

• How it Works: You store your primary data in Amazon S3 and retain only your frequently accessed data locally in a cache on the Storage Gateway. This significantly minimizes your on-premises storage footprint.

• Capacity: You can create volumes up to 32 TiB in size.

• Use Cases:

  • Primary storage for on-premises applications where you want to reduce local storage infrastructure and costs.

  • Applications that need low-latency access to their active dataset, while the full dataset can be much larger and stored durably in S3.

Stored Volumes Mode

• How it Works: You store the entire dataset locally on-premises, ensuring low-latency access to all your data. The gateway asynchronously backs up point-in-time snapshots of this data to Amazon S3 in the form of Amazon EBS Snapshots.

• Capacity: You can create volumes up to 16 TiB in size.

• Use Cases:

  • On-premises applications that require low-latency access to their entire dataset.

  • Implementing a robust, offsite backup and disaster recovery strategy. You can restore the EBS snapshots in EC2 to quickly recover your application in the cloud.

3. Tape Gateway (VTL)

Tape Gateway provides a durable, cost-effective, long-term archival solution by emulating a virtual tape library (VTL) in the cloud.

• How it Works: It presents a standard VTL interface that is compatible with leading backup software (e.g., Veeam, NetBackup, Dell EMC NetWorker). You can continue using your existing backup workflows while eliminating the operational costs of physical tape infrastructure.

• Data Flow:

  1. Your backup software writes data to virtual tapes on the gateway.

  2. The gateway stores these virtual tapes in Amazon S3 Standard.

  3. When you "eject" or "archive" a tape, the gateway moves it from S3 Standard to either S3 Glacier Flexible Retrieval or S3 Glacier Deep Archive, providing extremely low-cost, long-term storage.

• Use Cases:

  • Modernizing your backup and archival processes.

  • Replacing aging and costly physical tape libraries and offsite tape storage services.

  • Meeting long-term regulatory and compliance requirements for data retention.

Common Features & Deployment

• Deployment: The Storage Gateway is deployed on-premises as a virtual machine (supporting VMware ESXi, Microsoft Hyper-V, or Linux KVM) or as a pre-configured hardware appliance.

• Local Cache: All gateway types use a local disk cache to provide low-latency performance for your applications.

• Data Transfer: Data transferred from the gateway to AWS is encrypted (SSL/TLS) and optimized for efficient bandwidth utilization.