Amazon today released the beta version of its Storage Gateway, software that connects customers to its cloud data storage service. Storage Gateway automatically mirrors locally stored data to Amazon, allowing local access to data while providing a back-up copy in Amazon's cloud.

"The service provides low-latency performance by maintaining data in on-premises storage hardware while asynchronously uploading data to AWS (Amazon Web Services), where it is encrypted and securely stored in the Amazon Simple Storage Service (Amazon S3)," Amazon said in an announcement.

To use the service, customers download the Storage Gateway in the form of a VMware ESXi virtual machine, and then allocate on-premises disks to the gateway. Applications using the disks will write data to gateway volumes, keeping the data in-house while simultaneously uploading copies to the cloud, using SSL and at-rest encryption to preserve security. The service costs $125 per month for each gateway, plus usage charges for storage and data transfer.