The gateway sends backup snapshots of data to the cloud, while also storing the data locally. Snapshots can be used to readily restore the data to local hardware, and can be accessed as Amazon Elastic Block Store volumes for mirroring data between on-premises and Amazon apps that are based in the Elastic Compute Cloud, or EC2 .

Disaster Recovery, Data Migration

In a statement, Amazon said the gateways make it easy to use its EC2 "for additional capacity during peak periods, for new projects, or as a more cost-effective way to run normal enterprise workloads."

The company said it expected the AWS Storage Gateway would be used primarily for disaster recovery and business continuity, backup, and data migration. AWS cited the advantages of reducing costs for hardware by emphasizing a cloud strategy, and avoiding any concerns about running out of storage space or managing off-site facilities.

Storage volumes created with the gateway can be attached as iSCSI devices to on-site app servers. Amazon said the standard iSCSI interface worked with existing apps and on-premise architecture . Gateway-Stored volumes, available now, maintain a complete copy on local storage, while uploading backup snapshots to Amazon. Gateway-cached volumes, available soon, can use local storage as a low-latency cache for frequently used data, while the clean copy lives in the cloud.

Each gateway can support as many as 12 iSCSI volumes and a total of 12 terabytes, and there can be multiple gateways for each account. If different configurations are needed, users can request special arrangements. Users can choose to store data in any of Amazon's six regional centers, worldwide.

'One-Stop Shopping'

Gateways will automatically update themselves, which can be set to occur during a maintenance window, and each gateway reports a variety of metrics to Amazon for monitoring.

A Management Console allows an enterprise to create volumes, create or restore snapshots and establish scheduling. AWS users are eligible for a free trial for a limited time, after which the cost is $125 per activated gateway and, in the U.S.-East Region, $0.14 per gigabyte-month for snapshot storage. The cost-per-gigabyte falls as the amount of data usage increases.

Laura DiDio, an analyst with industry research firm Information Technology Intelligence Corp., said Amazon was attempting to provide a "one-stop shopping" solution with its gateways. She noted that it continued AWS' "stated strategy of addressing storage and data mirroring needs" in the enterprise, provided on a pay-as-you-go basis.

Last week, Amazon Web Services added a distributed database service called DynamoDB. It provides an on-demand, scalable database, with Amazon providing all management and provisioning. DynamoDB complements an earlier AWS database offering, SimpleDB.