AWS Storage Gateway
AWS Storage Gateway is a software appliance that runs in the customer’s data centre and backs local storage with AWS storage. On-premises applications keep using the protocol they already speak — NFS, SMB or iSCSI — while the authoritative copy of the data lives in Amazon S3, S3 Glacier or Amazon FSx.
It deploys as a virtual machine on VMware ESXi, Microsoft Hyper-V or KVM, as a hardware appliance ordered from a reseller, or as an AMI on Amazon EC2. AWS supplies the image; the hypervisor, the host and its capacity belong to the customer. It supports bandwidth throttling, so replication can be kept out of the way of production traffic.
The four gateway types
Section titled “The four gateway types”| Type | Interface | Where data lives | Typical use |
|---|---|---|---|
| Amazon S3 File Gateway | NFS, SMB | Amazon S3, cached locally | File shares, data-lake ingestion, general file storage |
| Amazon FSx File Gateway | SMB | Amazon FSx for Windows File Server, cached locally | Low-latency on-premises access to in-cloud Windows shares |
| Volume Gateway | iSCSI | Amazon S3, as EBS snapshots | Block storage, backup, disaster recovery, migration |
| Tape Gateway | iSCSI (virtual tape library) | S3 Glacier Flexible Retrieval, S3 Glacier Deep Archive | Replacing physical tape without changing backup software |
Volume Gateway has two modes, and the choice between them is the one that matters most in practice. Cached volumes keep the primary copy in S3 and only hot data locally, which suits migration and shrinking the on-premises footprint. Stored volumes keep the primary copy locally and replicate asynchronously to S3, which suits low-latency workloads that want cloud backup rather than cloud storage.
Old names
Section titled “Old names”AWS renamed the gateway modes some years ago and a great deal of material still uses the originals.
| Current name | Former name |
|---|---|
| Amazon S3 File Gateway | File Gateway (no earlier name) |
| Volume Gateway, stored mode | Gateway-stored volumes |
| Volume Gateway, cached mode | Gateway-cached volumes |
| Tape Gateway | Gateway-Virtual Tape Library |
Choosing between them
Section titled “Choosing between them”The first question is file or block. File-level access over NFS or SMB means S3 File Gateway (or FSx File Gateway where the shares are Windows shares already in FSx). Block-level access over iSCSI means Volume Gateway. S3 File Gateway and Volume Gateway cached mode look similar on a diagram — both keep the primary copy in S3 and cache locally — but they present fundamentally different things to the application, and an application that wants a block device cannot be given a file share.
The second question is whether this is a migration or an end state. A gateway is a permanent piece of infrastructure; if the goal is to move a dataset once and be done, AWS DataSync is the cheaper and simpler tool. The comparison page covers the overlap.