File Gateway Functional Principle

The File Gateway provides a virtual file server that can store and retrieve Amazon S3 objects by standard protocols such as NFS, allowing file-based devices and applications to use cloud storage transparently and without changes by simply offering a user's existing S3 buckets as NFS provisioning points. The applications then read and write files and directories via NFS, with the gateway translating file operations into object requests on the relevant S3 buckets.

The data last used is buffered on the gateway for quick access, and the data transfer to AWS is completely managed and optimized by the gateway. Unlike the Volume Gateway, users can immediately access their data in S3 as soon as synchronization with the gateway has taken place, including all S3 features such as life cycle policies, versioning, or cross-regional replication.

Tape Gateway Functional Principle

The Tape Gateway provides backup applications with a VTL interface consisting of a media changer and tape drives. The user creates virtual tapes in the VTL from the AWS Management Console. The backup application has read and write access to virtual tapes, which the user assigns to virtual tape drives with the virtual media changer. The virtual tapes from the relevant backup application are recognized by standard procedures for media inventory recording. Virtual tapes are also backed up by Amazon S3, whereas tape archiving takes place by AWS Glacier.

Prerequisites and Setup

If you want to try Storage Gateway, you need an AWS account. The gateway can be installed either on-premises or on an EC2 instance. In this article, I discuss the version to be installed locally, which AWS provides in the form of a virtual machine (VM). First, however, you have to choose one of the three types of gateway addressed in the deployment wizard.

Installing the VM requires at least 16GB of RAM, 80GB of drive space, and a quad-core processor on the host system. To install the Storage Gateway on the basis of an EC2 instance, you need at least one general-purpose instance (m3 or m4) of the size "xlarge." The gateway performs better with instance types i2, d2, c3, c4, or r3, depending on the workload characteristics of the applications accessing it.

In addition to the 80GB hard drive space for the VM itself, you will need additional drives if you are operating the Volume Gateway in stored mode, for example. You also need at least 150GB of caching space for the Volume Gateway, also in cached mode, and for the File and Tape gateways. Table 1 provides more information.

In the next step, you can download the gateway appliance. For local use, AWS provides a VM as an image for ESXi (OVA), Hyper-V 2008 R2, or Hyper-V 2012. The suitable gateway Amazon Machine Image (AMI) for use under EC2 is available from the AWS AMI Marketplace. However, deploying the OVA file under ESXi 6.5 in the web client did not work out of the box to an invalid manifest file, although it was no problem to deploy directly in the host client. The disks must be "thick" provisioned, and the ESXi host must be in sync with an NTP time server. If these requirements are met, the VM should be ready for use after a short time.

Next, connect to the IP address of the gateway in the wizard (i.e., wait for its provisioning process). Finally, you have to enable the gateway by defining the gateway time zone and the gateway name. The region has already been determined. Finally, click Activate gateway .

From this point on, costs arise. However, the free AWS contingent includes the first 100GB of data stored via the gateway. Additionally, the usual data storage prices for S3, plus the Storage Gateway-relevant storage prices for volume storage, EBS snapshots, or storage or archiving on virtual tapes are offered. Moreover, requisition prices and data transfer prices for S3 are always due. As usual with S3, incoming data is free of charge. For outgoing data, AWS differentiates between "data from the AWS Storage Gateway service to your gateway provided by Amazon EC2" and "transfer of outgoing data from the AWS Storage Gateway service to your local gateway," for which the first gigabyte per month is free of charge.

Once the Volume Gateway has been activated successfully, the wizard acknowledges with Gateway is now active . However, Configured local disk will still show No local disks found . After clicking Save and continue , you can continue with further configuration in the Management Console.