Part 2 – Azure Compute & Storage (Q21–40)
21. What is Azure Virtual Machine (VM)?
Answer
An Azure Virtual Machine (VM) is an Infrastructure as a Service (IaaS) offering that allows you to create and run Windows or Linux virtual servers in the cloud.
Key Features:
Full control over the operating system
Supports Windows and Linux
Auto Scaling (with VM Scale Sets)
High Availability
Backup and Disaster Recovery
Custom Images
Real-Time Example:
A banking application requires a Windows Server with SQL Server installed. The organization creates an Azure VM instead of purchasing a physical server.
Interview Tip:
Use Azure VM when you need complete control over the operating system.
22. What are the different VM sizes in Azure?
Answer
Azure provides different VM families for various workloads.
| VM Family | Purpose |
|---|---|
| B-Series | Low-cost burstable workloads |
| D-Series | General purpose applications |
| E-Series | Memory-intensive applications |
| F-Series | Compute-intensive workloads |
| M-Series | Large SAP and enterprise databases |
| N-Series | GPU and AI workloads |
Example:
B-Series → Development environment
D-Series → Web Application
E-Series → SQL Server
N-Series → Machine Learning
23. What is Azure VM Scale Set (VMSS)?
Answer
VM Scale Sets automatically increase or decrease the number of virtual machines based on workload.
Benefits
Auto Scaling
High Availability
Load Balancing
Cost Optimization
Real-Time Example
During an online shopping festival, traffic increases from 1,000 users to 100,000 users. VM Scale Sets automatically add more VMs.
24. What is Azure App Service?
Answer
Azure App Service is a Platform as a Service (PaaS) offering for hosting web applications, REST APIs, and mobile backends.
Supported Languages
.NET
Java
Node.js
Python
PHP
Go
Features
Auto Scaling
Built-in SSL
CI/CD Integration
Custom Domains
Deployment Slots
Real-Time Example
A company hosts its ASP.NET Core Web API on Azure App Service without managing servers.
25. Azure Virtual Machine vs Azure App Service
| Azure VM | Azure App Service |
|---|---|
| IaaS | PaaS |
| Full OS control | No OS management |
| Manual patching | Automatic patching |
| More maintenance | Less maintenance |
| Best for legacy applications | Best for modern web apps |
26. What is Azure Functions?
Answer
Azure Functions is a serverless compute service that runs code in response to events.
Triggers
HTTP
Timer
Blob Storage
Queue Storage
Event Hub
Service Bus
Benefits
No server management
Pay only for execution time
Automatic scaling
Real-Time Example
When a user uploads an image, an Azure Function automatically creates a thumbnail.
27. What is Azure Logic Apps?
Answer
Azure Logic Apps automate workflows and integrate applications using a low-code/no-code approach.
Common Integrations
Office 365
Outlook
SharePoint
SQL Server
SAP
Salesforce
Example
When an email with an attachment arrives, save the attachment to Azure Blob Storage and notify a Teams channel.
28. Difference between Azure Functions and Logic Apps
| Azure Functions | Logic Apps |
|---|---|
| Code-based | Low-code |
| Developers | Business users & developers |
| Complex logic | Workflow automation |
| Supports C#, JavaScript, Python | Drag-and-drop designer |
29. What is Azure Kubernetes Service (AKS)?
Answer
AKS is a managed Kubernetes service for deploying and managing containerized applications.
Features
Managed Kubernetes control plane
Auto Scaling
Rolling Updates
Self-Healing
Integrated Monitoring
Example
A microservices-based e-commerce platform runs in Docker containers orchestrated by AKS.
30. What is Azure Container Instances (ACI)?
Answer
Azure Container Instances allow you to run containers without managing virtual machines or Kubernetes clusters.
Use Cases
Short-lived jobs
Batch processing
Automation scripts
Development and testing
31. What is Azure Storage Account?
Answer
A Storage Account is the top-level Azure resource that provides access to Azure Storage services.
It can store:
Blob Storage
File Storage
Queue Storage
Table Storage
Example
A company stores invoices, backups, logs, and application files in a Storage Account.
32. What are the types of Azure Storage?
Answer
| Storage Type | Purpose |
|---|---|
| Blob Storage | Images, videos, files |
| File Storage | Shared network drives |
| Queue Storage | Messaging |
| Table Storage | NoSQL key-value storage |
| Disk Storage | VM disks |
33. What is Azure Blob Storage?
Answer
Azure Blob Storage stores unstructured data such as:
Images
Videos
PDFs
Backups
Log files
Blob Types
Block Blob
Append Blob
Page Blob
Real-Time Example
A social media application stores millions of user-uploaded photos in Blob Storage.
34. What is Azure File Storage?
Answer
Azure File Storage provides fully managed SMB and NFS file shares that can be accessed by multiple virtual machines simultaneously.
Example
Multiple application servers share configuration files through Azure File Storage.
35. What is Azure Queue Storage?
Answer
Queue Storage stores messages between application components, enabling asynchronous communication.
Real-Time Example
An online shopping application places order requests into a queue for background processing.
36. What is Azure Table Storage?
Answer
Azure Table Storage is a NoSQL key-value datastore for structured, non-relational data.
Best For
IoT data
User profiles
Device information
Metadata
37. What is Managed Disk in Azure?
Answer
Managed Disks are Azure-managed virtual hard disks used by Azure Virtual Machines.
Disk Types
Standard HDD
Standard SSD
Premium SSD
Premium SSD v2
Ultra Disk
Advantages
Automatic replication
High availability
Simplified management
38. What is Azure Backup?
Answer
Azure Backup is a cloud-based service that protects Azure resources and on-premises workloads.
Supports
Virtual Machines
SQL Server
Azure Files
SAP HANA
On-premises Servers
Features
Incremental backups
Long-term retention
Encryption
Centralized management
Real-Time Example
A company backs up production VMs every night and retains backups for seven years to meet compliance requirements.
39. What is Azure Site Recovery (ASR)?
Answer
Azure Site Recovery provides Disaster Recovery (DR) by replicating workloads to another Azure region or a secondary site.
Features
Continuous replication
Planned failover
Unplanned failover
Failback
Disaster recovery testing
Real-Time Example
If the primary region becomes unavailable, applications automatically fail over to a secondary region with minimal downtime.
40. What is the difference between Azure Backup and Azure Site Recovery?
| Azure Backup | Azure Site Recovery |
|---|---|
| Protects data | Protects entire applications and workloads |
| Recovery of files or VMs | Disaster recovery and business continuity |
| Scheduled backups | Continuous replication |
| Restore after deletion or corruption | Fail over during outages |
| Focuses on backup | Focuses on high availability and disaster recovery |
Part 2 Summary
In this section, you learned about:
Azure Virtual Machines (VMs)
VM Sizes and VM Scale Sets
Azure App Service
Azure Functions
Azure Logic Apps
Azure Kubernetes Service (AKS)
Azure Container Instances (ACI)
Azure Storage Accounts
Blob, File, Queue, and Table Storage
Managed Disks
Azure Backup
Azure Site Recovery (ASR)
Next: Part 3 (Q41–60) will cover Azure Networking & Security, including Virtual Networks (VNet), Subnets, Network Security Groups (NSGs), Azure Firewall, Load Balancer, Application Gateway, VPN Gateway, ExpressRoute, Azure Key Vault, Microsoft Entra ID (Azure AD), Managed Identities, Private Endpoints, DDoS Protection, and common networking interview scenarios.
