The Storage Gateway is aimed at enterprises and other users with on-premise data centers and applications. According to the product page:
The [AWS Storage Gateway] service enables you to securely upload data to the AWS cloud for cost effective backup and rapid disaster recovery. The AWS Storage Gateway supports industry-standard storage protocols that work with your existing applications. It provides low-latency performance by maintaining data on your on-premises storage hardware while asynchronously uploading this data to AWS, where it is encrypted and securely stored in the Amazon Simple Storage Service (Amazon S3).
Users create Gateway-managed storage volumes that are backed by both on-premise DAS/SAN and by S3. Two different types of volumes are envisioned:
- Gateway-Stored. The Gateway retains a complete replica of the volume on local storage, capturing snapshots periodically and storing them on Amazon S3.
- Gateway-Cached. Local volumes are used as a cache for data stored on S3, enhancing latency and performance for frequently-accessed data. Gateway-Cached mode is not available at launch, but is coming soon.
The AWS Storage Gateway presents an interesting contradiction in terms, in terms of data reliability and availability:
On the one hand, the appeal of using a gateway like this is to ensure that important data is backed up to the cloud; back-up and disaster recovery are top-line messages in Amazon’s descriptions of the product. At the same time, today’s Storage Gateway introduces a single point of failure between iSCSI-connected applications and the Gateway itself.
SAN users with mission-critical data may want to explore any failover configurations made possible by the underlying VMware ESXi platform before deploying the Storage Gateway.
DAS users will find using Gateway-Stored volumes a non-starter for truly mission-critical data, where a local replica would be required. It would be very interesting to see the snapshot-to-AWS functionality offered in conjunction with a scale-out storage offering such as Red Hat Storage (formerly Gluster) or Appistry’s CloudIQ Storage.
The AWS Storage Gateway is further indication of (a) the importance of enterprise users to AWS, and (b) the lengths they are willing to go to facilitate migrating existing data to S3. Offering on-premises software is a beast apart from running a cloud-based service, and one can only presume that Amazon thought long and hard about the complexity they were taking on in heading down this path, particularly from the customer support perspective. (Though they have attempted to minimize the support burden by offering the Gateway as a software appliance, currently only supported on VMware ESXi.)
The AWS Storage Gateway is not entering uncontested space. Companies like Nasuni and TwinStrata have offered cloud-backed on-premise appliances for quite some time. True to its commitment to commoditizing all aspects of cloud infrastructure, Amazon’s pricing is a fraction of that published by Nasuni, for example.
On the balance, the AWS Storage Gateway offers some interesting functionality for a subset of potential users, is a base upon which Amazon can continue to build on and add features, and demonstrates the company’s willingness to encroach upon the domain of the traditional Enterprise vendors in its mission to commoditize the cloud.