AZ-900 Describe Azure architecture and services Practice Question
A company has multiple on-premises file servers that store user home directories and department shares. The company wants to migrate these file shares to Azure Files to eliminate on-premises server maintenance. However, users frequently access large files, and the company wants to cache the most frequently accessed files locally on a small Windows Server machine at each branch office to minimize latency and bandwidth usage. The company also wants a single unified namespace so users can access files using the same path regardless of whether the files are cached locally or stored in Azure. Which Azure service should the company use?
⚠ Common exam trap
Candidates often confuse Azure File Sync with Azure Blob Storage or Azure Migrate, mistakenly thinking that blob storage with CDN can serve file shares or that a migration tool provides ongoing caching and synchronization, rather than recognizing that Azure File Sync is the only service that combines local caching, cloud tiering, and a unified SMB namespace.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Azure File Sync
Azure File Sync is the correct choice because it enables caching of frequently accessed files on a local Windows Server at each branch office while maintaining a single unified namespace (the same UNC path). It synchronizes files between Azure Files and on-premises servers, allowing users to access files locally for low latency and bandwidth savings, while changes are synced to Azure. This directly addresses the requirement to eliminate on-premises server maintenance by using Azure Files as the primary storage, with local caching for performance.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Azure Blob Storage with Azure Content Delivery Network (CDN)
Why it's wrong here
Azure Blob Storage is an object storage solution, not a file share. Azure CDN can cache content at edge locations but does not provide a unified namespace for SMB file shares or support on-premises caching of file shares.
When this WOULD be correct
A company needs to deliver large static media files (e.g., videos, images) globally with low latency. They use Azure Blob Storage as the origin and Azure CDN to cache content at edge locations, reducing load on the origin and improving user experience.
- ✓
Azure File Sync
Why this is correct
Azure File Sync enables you to centralize file shares in Azure Files while maintaining the flexibility, performance, and compatibility of an on-premises file server. It provides cloud tiering to cache frequently accessed files locally and transparently recalls files from Azure on demand, offering a single namespace.
- ✗
Azure Site Recovery
Why it's wrong here
Azure Site Recovery is a disaster recovery and business continuity service that continuously replicates virtual machines and physical servers from a primary site to a secondary location, enabling planned and unplanned failover with defined recovery point objectives (RPOs). While it does maintain replicated copies of entire workloads, its purpose is to protect against site-level outages, not to synchronize file shares or present a unified namespace across on-premises and Azure. It therefore lacks the file-level caching and transparent recall behavior found in Azure File Sync.
When this WOULD be correct
An exam question where a company needs to replicate on-premises workloads to Azure for business continuity and disaster recovery, with requirements for failover and failback of entire servers or applications.
- ✗
Azure Migrate
Why it's wrong here
Azure Migrate serves as a centralized hub for discovering and assessing on-premises infrastructure, then orchestrating the actual migration of servers, databases, and applications to Azure using tools like Azure Migrate: Server Migration. Its core function is to validate readiness and execute a one-time move of workloads, not to maintain ongoing file share synchronization. Consequently, it cannot deliver the continuous cloud tiering, local caching of hot files, or single SMB/UNC namespace that characterize Azure File Sync.
When this WOULD be correct
A company wants to assess and migrate its on-premises VMware VMs to Azure, including discovering dependencies and estimating costs. Azure Migrate would be the correct service to use for this migration assessment and execution.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The AZ-900 exam frequently reuses these exact scenarios with slightly different constraints.
✓Azure File SyncCorrect answer▾
Why this is correct
Azure File Sync enables you to centralize file shares in Azure Files while maintaining the flexibility, performance, and compatibility of an on-premises file server. It provides cloud tiering to cache frequently accessed files locally and transparently recalls files from Azure on demand, offering a single namespace.
✗Azure Blob Storage with Azure Content Delivery Network (CDN)Wrong answer — click to see why▾
Why this is wrong here
Azure Blob Storage with CDN provides global caching for static content but does not support SMB file sharing, unified namespace, or local caching of files from Azure Files. It cannot replace on-premises file servers for user home directories and department shares.
★ When this WOULD be the correct answer
A company needs to deliver large static media files (e.g., videos, images) globally with low latency. They use Azure Blob Storage as the origin and Azure CDN to cache content at edge locations, reducing load on the origin and improving user experience.
Why candidates choose this
Candidates may think CDN caching solves the latency issue for file access, but they overlook that Azure Files requires SMB protocol support and a unified namespace, which Blob Storage and CDN do not provide.
✗Azure Site RecoveryWrong answer — click to see why▾
Why this is wrong here
Azure Site Recovery is a disaster recovery service that replicates virtual machines and physical servers to Azure for failover, not for caching file shares or providing a unified namespace for file access.
★ When this WOULD be the correct answer
An exam question where a company needs to replicate on-premises workloads to Azure for business continuity and disaster recovery, with requirements for failover and failback of entire servers or applications.
Why candidates choose this
Candidates may confuse 'recovery' with 'caching' or think Site Recovery can help with file availability, but it is designed for disaster recovery, not file caching or sync.
✗Azure MigrateWrong answer — click to see why▾
Why this is wrong here
Azure Migrate is a tool for discovering, assessing, and migrating on-premises workloads to Azure, but it does not provide local caching or a unified namespace for file shares. It cannot cache files locally on branch office servers or present a single path for cached and cloud files.
★ When this WOULD be the correct answer
A company wants to assess and migrate its on-premises VMware VMs to Azure, including discovering dependencies and estimating costs. Azure Migrate would be the correct service to use for this migration assessment and execution.
Why candidates choose this
Candidates may confuse Azure Migrate with a file migration solution because the question involves migrating file shares, leading them to think a general migration tool is appropriate.
Analysis generated from the official AZ-900blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Go deeper
Related to this question
Learn chapter
Azure Regions and Geographies
Key term
User
A user is any person, system, or device that interacts with an IT service, resource, or identity system, typically authenticated through credentials and authorized to perform specific actions.
Key term
Azure Files
Azure Files is a cloud-based file sharing service that lets you create and access file shares using the Server Message Block (SMB) protocol or Network File System (NFS) protocol, just like you would access files on a local network drive.
About these practice questions
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This AZ-900 practice question is part of Courseiva's free Microsoft certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the AZ-900 exam.