Describe Azure architecture and services
Azure Storage and Migration
CoreChoose storage services, access tiers, redundancy, file tools, and migration services.
Aligned to the AZ-900 skills measured as of July 20, 2026; product behavior verified August 23, 2026.
Why this matters
Storage questions combine several independent decisions: data shape, access pattern, copy durability, account capability, movement interface, and migration method.
Must Know
- Blob Storage holds unstructured object data; Azure Files provides managed file shares; Queue Storage holds messages; Table Storage holds schemaless key-value data; managed disks provide block storage for Azure VMs.
- Blob access tiers reflect frequency, latency, retention, and cost trade-offs: hot for frequent access, cool/cold for less frequent online access, and archive for rarely accessed offline data that can tolerate rehydration delay.
- Redundancy maintains copies at different failure scopes. LRS keeps copies in one datacenter, ZRS spreads copies across zones in one region, and geo options replicate to a secondary region; read-access geo options expose the secondary for reads.
- A storage account type determines supported services, performance choices, tiers, and redundancy combinations; not every account supports every option.
- AzCopy is a command-line copy tool; Storage Explorer is a graphical storage-management tool; Azure File Sync synchronizes Azure file shares with Windows Servers and supports local caching.
- Azure Migrate supports discovery, assessment, and migration scenarios; Azure Data Box uses a Microsoft-supplied appliance for large offline data transfer.
Compare and Distinguish
- Blob vs Files vs Queue vs Table vs Disk: object, shared-file, message, key-value, and VM block storage.
- Tier vs redundancy: access/cost behavior versus where durable copies are maintained.
- AzCopy vs Storage Explorer vs File Sync: command copy, graphical management, and ongoing synchronization/caching.
- Azure Migrate vs Data Box: migration assessment/coordination versus appliance-based data transfer.
Scenario examples
- An application stores images in Blob Storage and decouples components with Queue Storage.
- Frequently read objects use a hot tier while compliance archives that tolerate retrieval delay use archive.
- A Windows file server retains a local cache while synchronizing with Azure Files through File Sync.
- A very large dataset with limited network capacity moves through Data Box.
Exam traps
- Archive is an access tier, not a redundancy choice.
- Redundancy is not the same as a separately managed backup.
- File Sync is not merely a one-time copy utility.
- Azure Migrate and Data Box address different parts of migration.
Key takeaways
- Choose the service from the data shape first.
- Choose access tier and redundancy independently.
- Choose the movement tool from command, graphical, sync, assessment, or offline-appliance needs.
Ready for the quiz?
- Which service stores messages between components?
- How does access tier differ from redundancy?
- When is Data Box a better fit than Azure Migrate?
Related objectives
- D2.3.S1 — Compare Azure Storage services
- D2.3.S2 — Describe storage tiers
- D2.3.S3 — Describe redundancy options
- D2.3.S4 — Describe storage account options and storage types
- D2.3.S5 — Identify options for moving files, including AzCopy, Azure Storage Explorer, and Azure File Sync
- D2.3.S6 — Describe migration options, including Azure Migrate and Azure Data Box