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A Virtual Machine (VM) is a software-based computer that runs inside a physical computer (host machine). It behaves like a real computer and has its own Operating System, CPU, Memory (RAM), Storage, and Network.
A VM uses virtualization technology, which allows multiple virtual machines to run on a single physical server while sharing the server's hardware resources.
Each Virtual Machine works independently, so a problem in one VM does not affect the other VMs running on the same host.
In simple words:
A Virtual Machine is a virtual computer that functions like a physical computer but runs inside another computer.
Components of a Virtual Machine
Every Virtual Machine consists of the following components:
These virtual components work together to provide the same functionality as a physical computer.
Virtualization is the technology that allows multiple Virtual Machines to run on a single physical server.
Instead of purchasing separate physical servers for different applications, virtualization enables one physical server to host several independent virtual machines.
Each VM has:
Virtualization improves hardware utilization and reduces infrastructure costs.
Hypervisor
A Hypervisor is software that creates and manages Virtual Machines.
It allocates hardware resources such as CPU, RAM, Storage, and Networking to each VM.
The Hypervisor also isolates one VM from another to ensure security and stability.
Examples of Hypervisors:
An Azure Virtual Machine (Azure VM) is an on-demand virtual server provided by Microsoft Azure.
Instead of purchasing physical hardware, users can create virtual servers in Azure within a few minutes and access them over the internet.
Azure manages the underlying physical infrastructure, while users manage the operating system, applications, and data inside the VM.
Azure Virtual Machines support both:
IaaS (Infrastructure as a Service) is a cloud computing service model in which a cloud provider delivers virtualized computing resources such as virtual machines, storage, networking, and other infrastructure over the internet.
Instead of purchasing and maintaining physical servers, organizations can rent these resources on demand and pay only for what they use.
In Microsoft Azure, Azure Virtual Machines (Azure VMs) are one of the most common examples of IaaS.
In the IaaS model, the cloud provider is responsible for managing the physical infrastructure, while the customer is responsible for managing the virtual machine and everything inside it.
Cloud Provider (Microsoft Azure) Manages:
Customer Management:
Azure VM is considered an IaaS service because Microsoft manages the physical infrastructure while the customer manages the virtual machine.
Microsoft Azure Manages:
Customer Manages:
This shared responsibility allows organizations to focus on their applications without maintaining physical hardware.
| Physical Server | Virtual Machine |
| Physical hardware | Software-based computer |
| Requires dedicated hardware | Runs on shared physical server |
| Higher hardware cost | Lower infrastructure cost |
| Difficult to scale | Easy to scale |
| Longer deployment time | Can be deployed within minutes |
| Hardware maintenance required | Azure manages hardware |
Azure Virtual Machines are widely used in organizations for various business requirements.
Common use cases include:
1. Hosting Business Applications
Organizations host ERP, CRM, HRMS, and other business applications on Azure VMs.
2. Domain Controllers
Windows Server Virtual Machines can be configured as:
3. Web Server Hosting
Azure VMs can host:
4. Database Servers
Organizations use Azure VMs for hosting:
5. Development and Testing
Developers create temporary virtual machines for:
After testing, the VM can be deleted to reduce costs.
6. Backup and Disaster Recovery
Azure VMs help organizations recover quickly during hardware failures or disasters by restoring workloads from backups.
7. Remote Desktop Environment
Employees can securely connect to Windows Virtual Machines using Remote Desktop Protocol (RDP) and work from any location.
Benefits of Azure Virtual Machines
What is Azure VM architecture?
Azure VM architecture refers to the complete set of Azure resources and components that work together to successfully create, deploy, and manage a Virtual Machine in Microsoft Azure.
A Virtual Machine cannot function independently in Azure. It requires supporting resources such as a Resource Group, Virtual Network, Subnet, Network Interface, IP Address, Storage Disks, and an Azure Region.
Each component has a specific role in ensuring the VM operates securely and efficiently.
The main components of Azure VM Architecture are:
What are Azure VM Sizes?
Azure Virtual Machine (VM) Sizes define the amount of computing resources allocated to a Virtual Machine. These resources include the number of Virtual CPUs (vCPUs), Memory (RAM), Storage capacity, and Network performance.
When creating a Virtual Machine in Azure, selecting the appropriate VM size is important because it directly affects the performance, scalability, and cost of the VM.
Microsoft Azure provides different VM sizes to meet various business and application requirements. Small applications require fewer resources, whereas enterprise applications require larger VM sizes with higher CPU and memory.
Choosing the correct VM size helps organizations optimize performance while controlling cloud costs.
VM Sizes are important because every application has different hardware requirements.
For example:
Selecting the correct VM size ensures:
Microsoft Azure provides several categories of virtual machine sizes. The most commonly used VM categories are:
General-purpose virtual machines provide a balanced combination of CPU and Memory resources.
These VMs are designed for applications that require moderate processing power and moderate memory.
General Purpose VMs are commonly used for:
Examples:
Advantages
Compute Optimized Virtual Machines provide more CPU power compared to memory.
These VMs are designed for applications that perform heavy calculations and require high processing performance.
Common use cases include:
Example: F-Series
Advantages
Memory Optimized Virtual Machines provide a larger amount of RAM than CPU resources.
These VMs are designed for applications that process large amounts of data in memory.
Common use cases include:
Examples:
Advantages
Azure VM Pricing
Azure Virtual Machine pricing depends on several factors.
The more resources allocated to a VM, the higher its cost.
Azure follows a flexible pricing model that allows organizations to pay only for the resources they consume.
1. CPU (vCPU)
The number of Virtual CPUs assigned to a VM directly affects its price.
Higher CPU resources provide better performance but increase the overall cost.
2. Memory (RAM)
Virtual Machines with more RAM are more expensive because they support memory-intensive workloads such as databases and analytics applications.
3. Storage
The size and type of storage attached to the VM also affect pricing.
Azure provides different storage options such as:
Premium SSD offers better performance but costs more than Standard HDD.
4. Azure Region
Pricing varies depending on the Azure Region where the VM is deployed.
Some regions have lower operational costs, while others may be more expensive.
Selecting the nearest region also improves application performance by reducing network latency.
5. Operating System
The operating system installed on the Virtual Machine also affects pricing.
6. Usage Duration
Azure charges for the amount of time a Virtual Machine is running.
If the VM is stopped and deallocated, compute charges stop, helping reduce costs.
Organizations often stop unused VMs during non-working hours to save money.
Azure uses the Pay-as-you-go pricing model.
In this model, customers pay only for the resources they actually use.
There is:
Organizations can create, resize, or delete Virtual Machines whenever required and are billed based on actual usage.
Benefits of Pay-as-you-go
What is VM Storage?
VM Storage refers to the storage resources attached to an Azure Virtual Machine for storing the operating system, applications, user files, databases, and other data.
Every Azure VM requires at least one OS Disk, and additional Data Disks can be attached based on storage requirements.
Types of Azure VM Disks
Azure Virtual Machines mainly use two types of disks:
Azure stores these disks as Managed Disks, which are fully managed by Microsoft Azure.
What is an OS Disk?
An Operating System (OS) Disk is the primary disk that contains the operating system required to boot and run the Virtual Machine.
Examples:
Every Azure Virtual Machine must have one OS Disk.
Uses of OS Disk
What is a Data Disk?
A Data Disk is an additional storage disk attached to a Virtual Machine to store application data, user files, databases, backups, and logs.
Unlike the OS Disk, it does not contain the operating system.
A Virtual Machine can have multiple Data Disks depending on its size.
Uses of Data Disk
What is a Managed Disk?
A Managed Disk is a virtual hard disk that is fully managed by Microsoft Azure.
Azure automatically handles storage management, availability, security, backup integration, and scalability, allowing administrators to focus on managing the Virtual Machine instead of the storage infrastructure.
Benefits of Managed Disks
Azure provides different types of managed disks based on performance requirements.
1. Standard HDD
Standard HDD is a magnetic hard disk designed for basic workloads where high performance is not required.
Suitable for:
2. Standard SSD
Standard SSD provides better performance than Standard HDD and is suitable for everyday business applications.
Suitable for:
3. Premium SSD
Premium SSD offers high performance and low latency. It is recommended for production workloads that require fast storage access.
Suitable for:
| OS Disk | Data Disk |
| Contains the operating system | Stores application and user data |
| Required for every VM | Optional |
| Used to boot the VM | Cannot boot the VM |
| Usually one per VM | Multiple disks can be attached |
What is VM Security?
VM Security refers to the methods and security features used to protect Azure Virtual Machines from unauthorized access, cyber threats, and data breaches. Azure provides multiple security features to secure VMs and their network communication.
What is a Network Security Group?
A Network Security Group (NSG) is a security feature in Azure that controls inbound and outbound network traffic to Virtual Machines using security rules.
It acts like a firewall by allowing or denying network traffic based on ports, protocols, and IP addresses.
Benefits of NSG
What are Firewall Rules?
Firewall Rules define which network traffic is allowed or blocked for a Virtual Machine.
Administrators open only the required ports to reduce security risks.
Common Ports:
What is Just-in-Time (JIT) Access?
Just-in-Time (JIT) Access is an Azure security feature that keeps management ports such as RDP (3389) and SSH (22) closed by default.
When an administrator needs to access the VM, they request temporary access for a specific period. After the approved time expires, the ports are automatically closed again.
Benefits of JIT Access
What is Azure Backup?
Azure Backup is a cloud-based service that creates secure backups of Virtual Machines and their data. It helps recover data in case of accidental deletion, hardware failure, ransomware attacks, or disasters.
Benefits of Azure Backup
What is Patching?
Patching is the process of installing software updates, security fixes, and bug fixes on the operating system and applications running inside a Virtual Machine.
Regular patching helps protect the VM from vulnerabilities and improves system stability.
Benefits of Patching
What is Backup & Availability?
Backup and Availability are important Azure features that help protect Virtual Machines from data loss, hardware failures, and unexpected downtime. They ensure that applications remain available and business operations continue without interruption.
What is Azure Backup?
Azure Backup is a cloud-based backup service that securely stores copies of Virtual Machines and their data. It allows administrators to restore data if it is accidentally deleted, corrupted, or lost due to system failures.
Benefits of Azure Backup
What is a Snapshot?
A Snapshot is a point-in-time copy of a Virtual Machine disk. It captures the current state of the disk and can be used to restore data or create new disks when required.
Benefits of Snapshots
What is an Availability Set?
An Availability Set is an Azure feature that distributes multiple Virtual Machines across different Fault Domains and Update Domains.
If one physical server fails or Azure performs maintenance, the other Virtual Machines remain available, minimizing downtime.
Benefits of Availability Set
What is an Availability Zone?
An Availability Zone is a physically separate data center within an Azure Region, each having its own power, cooling, and networking.
If one Availability Zone fails, Virtual Machines in another zone continue running, ensuring high availability.
Benefits of Availability Zone
| Availability Set | Availability Zone |
| Protects against server and maintenance failures | Protects against complete data center failures |
| VMs are placed within the same Azure Region | VMs are placed in different physical zones of the same region |
| Uses Fault Domains and Update Domains | Uses physically separate data centers |
| Suitable for protecting against hardware failures | Suitable for maximum availability and disaster recovery |
