Azure Storage services and account types¶
Azure Storage provides durable cloud data services for objects, files, queues, tables, and disks. AZ-900 tests which storage type fits a workload and which account kind supports it.
Core storage services¶
| Service | Stores | Typical use |
|---|---|---|
| Blob Storage | Unstructured objects such as images, video, backups, logs, and documents | Data lake, app uploads, static content, backup targets |
| Azure Files | Managed file shares using SMB or NFS | Lift-and-shift file shares, shared config, legacy apps needing a file share |
| Queue Storage | Large numbers of messages | Decouple application components asynchronously |
| Table Storage | NoSQL key-value data | Simple structured data at scale |
| Azure Disks | Block storage for VMs | OS and data disks for Azure Virtual Machines |
Exam rules:
- objects such as images, video, backups → Blob Storage;
- managed SMB/NFS share → Azure Files.
Storage account¶
A storage account is the container that holds your Azure Storage data services. Every blob, file share, queue, and table belongs to a storage account.
When creating a storage account, important choices include:
- account type or performance tier;
- replication option;
- access tier defaults for blobs;
- public access and networking settings.
Common account types¶
| Account type | Typical exam note |
|---|---|
| Standard general-purpose v2 | Default choice for blobs, files, queues, and tables |
| Premium block blobs | Low-latency, high-transaction blob workloads |
| Premium file shares | High-performance file shares |
| Premium page blobs | Legacy page blob scenarios; disks use Azure Managed Disks for VMs |
For most AZ-900 questions, general-purpose v2 is the standard answer unless the scenario calls out premium performance.
Blob types¶
| Blob type | Best for |
|---|---|
| Block blobs | Text and binary data, files, streaming objects, documents |
| Append blobs | Logging with append operations |
| Page blobs | Random read/write patterns in page-sized blocks; legacy VHD-style scenarios |
Most object-storage scenarios on the exam map to block blobs.
Scenario¶
A mobile app uploads photos and videos that must be stored as objects and served globally.
Best fit: Blob Storage in a general-purpose v2 account, often with a hot or cool tier depending on access frequency.
Scenario¶
An on-premises application expects a UNC path to a shared Windows file share in Azure.
Best fit: Azure Files.
Exam clues¶
- Unstructured object data → Blob.
- Shared file share → Azure Files.
- Messages between app tiers → Queue Storage.
- VM disk → Azure Managed Disks, backed by storage designed for VMs rather than a user-managed blob file share.