AWS Storage Gateway

The AWS Storage Gateway is a service connecting an on-premises software appliance with cloud-based storage to provide seamless and secure integration between an organization's on-premises IT environment and AWS's storage infrastructure. The service enables you to securely store date to the AWS cloud for scalable and cost-effective storage.

AWS Storage Gateway's software appliance is available for download as a virtual machine (VM) image that you install on a host in your datacenter. Storage Gateway supports either VMware ESXi or Microsoft Hyper-V. Once you've installed your gateway and associated it with your AWS account through the activation process, you can use the AWS Management Console to create the storage gateway option that is right for you.

Four Types of Storage Gateways

  • File Gateway (NFS): Flat files are stored directly on S3.
  • Volumes Gateway (iSCSI): Block storage. e.g. a virtual hard drive.
    • Stored Volumes: Store an entire copy of your data on-premises. Backed up as a snapshot to S3 asynchronously.
    • Cached Volumes: Only storing the most recently accessed on-premises.
  • Tape Gateway (VTL): Used for backup and uses popular backup applications like NetBackup, Backup Exec, Veeam, etc.

For the AWS Solutions Architect exam, know these four types at a high level and their use cases.

File Gateway

Files are stored as objects in your S3 buckets, accessed through a Network File System (NFS) mount point. Ownership, permissions, and timestamps are durably stored in S3 in the user-metadata of the object associated with the file. Once objects are transferred to S3, they can be managed as native S3 objects, and bucket policies such as versioning, lifecycle management, and cross-region replication apply directly to object stored in your bucket.


Volume Gateway

The volume interface presents your applications with disk volumes using the iSCSI block protocol. You can store operating systems, applications, databases, etc. Think of this as a virtual hard disk.

Data written to these volumes can be asynchronously backed up as point-in-time snapshots of your volumes, and stored in the cloud as Amazon EBS snapshots. EBS (Elastic Block Stores) are virtual hard disks that are usually attached to EC2 instances.

Snapshots are incremental backups that capture only changed blocks. On changes from the last snapshot are stored. All snapshot store is also compressed to minimize your storage charges.

Stored Volumes

Stored volumes let you store your primary data locally, while asynchronously backing up that data to AWS. Stored volumes provide your on-premises applications with low-latency access to their entire datasets, while providing durable, off-site backups. You can create storage volumes and mount them as iSCSI devices from your on-premises application servers. Data written to your stored volumes is stored on your on-premises storage hardware. This data is asynchronously backed up to S3 in the form of Amazon Elastic Block Store (Amazon EBS) snapshots. 1GB - 16TB in size for Stored Volumes.

You keep a complete copy of your data on-site.

Cached Volumes

Cached volumes let you use S3 as your primary data storage while retaining frequently accessed data locally in your storage gateway. Cached volumes minimize the need to scale your on-premises storage infrastructure, while still providing your applications with low-latency access to their frequently access data. You can create storage volumes up to 32TB in size and attach to them as iSCSI devices from your on-premises application servers. Your gateway stores data that you write to these volumes in Amazon S3 and retains recently read data in your on-premises storage gateway's cache and upload buffer storage. 1GB - 32TB in size for Cached Volumes.

You do not keep a complete copy of your data on-site.

Tape Gateway

Tape Gateway offers a durable, cost-effective solution to archive your data in the AWS Cloud. The VTL inferface it provides lets you leverage your existing tape-based backup application infrastructure to store data on virtual tape cartridges that you create on your tape gateway. Each tape gateway is preconfigured with a media charger and tape drives, which are available to your existing client backup applications as iSCSI devices. You add tape cartridges as you need to archive your data. Supported by NetBackup, Backup Exec, Veeam, etc.