Tape Gateway – Designing Networks for Complex Organizations – SAP-C02 Study Guide

Tape Gateway

Tape Gateway offers a virtual tape library (VTL) service backed by storage on Amazon S3 and accessible on-premises through the standard iSCSI protocol.

Concretely, Tape Gateway comes either as a preset hardware appliance or as a software appliance that you deploy in your on-premises environment. The software appliance consists of a VM that can run either on VMware ESX, Microsoft Hyper-V, or a Linux KVM hypervisor (but also on Amazon EC2 instances, should you need to).

As illustrated in the following diagram, Tape Gateway provides a VTL infrastructure that scales seamlessly, without the burden of having to operate or maintain the tape infrastructure on-premises. It integrates with the most popular backup solutions on the market, so chances are high that you can keep using your existing backup application. Now, the major difference from your previous physical tape solution or VTL solution is that Tape Library will store your virtual tapes in the cloud on Amazon S3. When your backup application sends data to the tape gateway, the data is first stored locally on the gateway and then copied over to the virtual tapes on Amazon S3 asynchronously:

Figure 2.11: Tape gateway

Just as with any VTL solution, Tape Gateway proposes the concepts of a tape drive and media changer. Both the tape drive and media changer are available to your backup application as iSCSI devices.

The tape archive also offers the possibility to archive your tapes. When your backup application instructs Tape Gateway to archive a tape, the tape will be moved to a lower-cost storage tier using Amazon S3 Glacier or Amazon S3 Glacier Deep Archive.

Additional Considerations

To wrap up what was just covered, AWS Storage Gateway offers three different types of gateways to enable a hybrid storage architecture across your on-premises infrastructure and your AWS environment. You leverage each of these three types depending on the use case at stake—File Gateway when setting up a hybrid file server infrastructure, Volume Gateway when expanding your block storage infrastructure to the cloud, and Tape Gateway for replacing your physical tape infrastructure with virtual tapes on AWS.

The following section will take you through a few additional considerations to better plan the actual implementation of such a hybrid storage infrastructure.

Resiliency

The gateway, hardware, or software appliance is by default a SPOF. So, what are your options to deal with any type of failure, for instance, if a component crashes or at least stops responding, whether it is due to the appliance, the hypervisor, the network, and so on?

In the case of a software appliance that you deploy on VMware ESXi, you have an option to enable high availability (HA) using VMware HA. AWS Storage Gateway provides a series of application health checks that VMware HA can interpret to automatically recover your storage gateway when the health-check thresholds you specify are breached. That will cater to most failure cases.

This option is most useful when organizations cannot tolerate a long interruption of service or any data loss.