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Chapter 18 of 20

Storage Gateway & Migration Services

Domain 4 — Cost-Optimized Architectures (20%)
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Question 1Scenario

An on-premises company wants their applications to continue using NFS and SMB file protocols to access files, while the actual data is stored durably in Amazon S3. Which AWS Storage Gateway type provides this?

Explanation

AWS Storage Gateway types: (1) S3 File Gateway — NFS/SMB access to S3. (2) FSx File Gateway — SMB access to FSx for Windows. (3) Volume Gateway — iSCSI block storage (Stored: primary on-prem + async S3 backup; Cached: primary in S3 + local cache). (4) Tape Gateway — virtual tape library for backup software.

Question 2Scenario

A company needs to migrate 80 TB of data from an on-premises data centre to Amazon S3. Their internet connection is 1 Gbps but is heavily used for business operations. The migration must complete within 2 weeks. What is the MOST appropriate transfer method?

Explanation

AWS Snow Family rule of thumb: if transferring over the internet would take more than 1 week, use a Snowball device. Snowball Edge Storage Optimised holds 80 TB usable storage. For very large migrations (petabytes), use multiple Snowball devices or Snowmobile (45-foot shipping container, up to 100 PB). DataSync is best for ongoing or incremental transfers after the initial bulk migration.

Question 3Scenario

A company wants to migrate their on-premises Oracle database to Amazon Aurora PostgreSQL with minimal downtime. They need continuous replication during the migration period so the cutover window is just a few minutes. Which service handles this?

Explanation

DMS supports homogeneous migrations (Oracle to RDS Oracle) and heterogeneous migrations (Oracle to Aurora, SQL Server to MySQL). For heterogeneous migrations, use AWS Schema Conversion Tool (SCT) to convert the schema first, then DMS for data migration with ongoing replication. The source database stays live during migration, minimising downtime.

Question 4Knowledge

Which Storage Gateway (Volume Gateway) configuration stores ALL primary data in Amazon S3 while caching only the most frequently accessed data locally on-premises?

Explanation

Volume Gateway modes: Stored — complete copy on-premises, async EBS snapshot to S3 (low latency for all data, high local storage required). Cached — complete copy in S3, local cache for hot data (minimises local storage requirement, slightly higher latency on cache miss). Cached mode is preferred when local storage is limited.

Question 5Scenario

A company wants to retire their physical tape backup infrastructure while keeping their existing backup software (e.g., Veeam, Commvault) working without modification. Which AWS service replaces physical tapes?

Explanation

Tape Gateway emulates a physical tape library over iSCSI, with virtual tape drives and a virtual tape shelf. Backup software writes to virtual tapes as if they were physical tapes. Virtual tapes are stored in S3, and archived tapes are moved to S3 Glacier or Glacier Deep Archive. This is a zero-change path to the cloud for tape-based backup workflows.