1. Overview

AWS Storage Gateway is a hybrid cloud storage service that connects your on-premises environment to AWS cloud storage. It provides a local cache for low-latency access while seamlessly integrating with S3, EBS, and Glacier.

Core Concept Storage Gateway bridges on-premises storage and AWS. Your applications access the gateway using standard storage protocols (NFS, SMB, iSCSI), and the gateway transfers data to AWS in the background. It solves: backup to cloud, tiered storage, DR, and migration.

2. Gateway Types


S3 File Gateway

  1. Presents S3 buckets as NFS or SMB file shares to on-premises applications
  2. Files are stored as objects in S3 (1:1 mapping)
  3. Local cache on the gateway for recently accessed files (low-latency reads)
  4. Supports S3 Standard, Standard-IA, One Zone-IA, Intelligent-Tiering
  5. Lifecycle rules on S3 can transition data to Glacier
  6. Integrated with Active Directory for SMB authentication

Use for: On-premises applications that need to store/access files in S3 using standard file protocols.


FSx File Gateway

  1. Provides on-premises access to Amazon FSx for Windows File Server
  2. Local cache for frequently accessed data
  3. SMB protocol, Active Directory integration
  4. Useful when you need a Windows file share backed by FSx but accessed from on-premises


Volume Gateway

  1. Presents iSCSI block storage volumes to on-premises applications
  2. Volumes are backed by S3 as EBS snapshots

Tape Gateway

  1. Presents a virtual tape library (VTL) interface to backup applications
  2. Backup software writes to virtual tapes via iSCSI
  3. Virtual tapes are stored in S3. Archived tapes go to S3 Glacier or Deep Archive.
  4. Compatible with: Veeam, Veritas NetBackup, Commvault, etc.


Use for: Replacing physical tape libraries with cloud-backed virtual tapes. Tape backup to AWS.

3. Storage Gateway Summary

4. When to use

Use Storage Gateway when you need to connect on-premises environments to AWS cloud storage seamlessly using standard storage protocols.

Common scenarios:

  1. Hybrid cloud storage — Extend on-premises storage to AWS without changing existing workflows.
  2. Cloud backup — Back up on-premises data to S3, S3 Glacier, or EBS.
  3. Disaster recovery — Keep cloud-based copies of on-premises data.
  4. Migrate data gradually — Move data to AWS over time without a full cutover.
  5. Low-latency local access — Cache frequently used data on-premises while storing the full dataset in AWS.
  6. Tape replacement — Replace physical tape infrastructure with virtual tapes in AWS.


Exam Tip Storage Gateway: "On-premises NFS/SMB access to S3" = S3 File Gateway. "On-premises Windows SMB + FSx" = FSx File Gateway. "On-premises iSCSI block storage backed by S3" = Volume Gateway. "Replace tape backups" = Tape Gateway. "Cached vs Stored": Cached = primary in cloud; Stored = primary on-premises.