Azure Storage

Difficulty: medium

Overview

Azure Blob Storage is Microsoft's object storage service for unstructured data — documents, images, videos, backups, and logs.

Storage Account Types:

General-purpose v2 (GPv2): Recommended for all scenarios. Supports Blob, File, Queue, and Table storage.
Premium Block Blob: SSD-based; for high-transaction, low-latency workloads.

Blob Types:

Block Blob: Most common. Optimized for sequential read/write. Used for files, media, and backups.
Append Blob: Append-only; ideal for logging scenarios.
Page Blob: Random read/write; used for Azure VM OS and data disks (VHDs).

Access Tiers:

Tier	Use Case	Storage Cost	Access Cost	Min Duration
Hot	Frequent access	Highest	Lowest	None
Cool	Infrequent (~monthly)	Medium	Medium	30 days
Cold	Rare (~quarterly)	Lower	Higher	90 days
Archive	Long-term archival	Lowest	Highest	180 days

Archive blobs are offline — retrieval (rehydration) takes hours.

Redundancy Options (cheapest → most resilient):

LRS: 3 copies in one data center. Protects against hardware failures.
ZRS: 3 copies across 3 AZs in one region. Protects against AZ failures.
GRS: LRS in primary + async replication to a secondary region. Failover required to read from secondary.
RA-GRS: GRS + read access to the secondary region endpoint at all times.
GZRS / RA-GZRS: ZRS in primary + async secondary region replication.

Access Control:

Storage Account Keys: Full account access; use sparingly; rotate regularly.
Shared Access Signatures (SAS): Delegated, time-limited, scoped tokens — recommended for external or temporary access.
Azure RBAC: Use Storage Blob Data Reader/Contributor roles for Azure-native identities — preferred over keys.

Practice Linked Questions

easy

Q1. A company stores log files accessed approximately once a month. Instant retrieval is required when accessed. Which Azure Blob Storage access tier minimizes storage cost?

Select one answer before revealing.

hard

Q2. A vendor running scripts outside Azure needs write-only access to a specific Blob Storage container for exactly 7 days, with no ongoing Azure credentials. What is the correct approach?

Select one answer before revealing.