A virtual machine does not exist in a vacuum. It is a composite entity constructed from several interconnected, foundational Azure resources. For IT project managers and architects, understanding this bill of materials is critical for accurate cost forecasting and governance.
Every Azure Virtual Machine deployment must be assigned to an Azure Resource Group—a logical container used to group, govern, and monitor related resources. Within that group, the virtual machine relies on several mandatory and optional components to function.
Core Compute Resources
An Azure Virtual Machine requires a selected compute size during deployment. This decision fundamentally dictates the hourly cost of the machine because the selected compute size determines the amount of CPU resources allocated to an Azure Virtual Machine, as well as the amount of memory resources allocated. Whether processing lightweight active directory requests or rendering complex 3D models, the compute size dictates the engine's horsepower.
Persistent Storage
Virtual machines inherently require a place to install their operating system and store data. An Azure Virtual Machine requires at least one storage disk to serve as the operating system drive. To support this, Azure managed disks provide the persistent block-level storage required by Azure Virtual Machines. These managed disks exist independently of the compute instance, ensuring that if the virtual machine is deallocated or moved, the underlying data remains intact and secure.
Network Connectivity
A computer without a network connection is effectively useless. An Azure Virtual Machine requires a Virtual Network to enable network communication with other resources, the internet, or on-premises environments. To bridge the compute instance to this network, an Azure Virtual Machine deployment requires the creation of a Network Interface Card (NIC). This Network Interface Card physically links an Azure Virtual Machine to a specific subnet within an Azure Virtual Network.
Azure also provides powerful, optional networking resources to govern access and security:
- Public IP Address: A Public IP address is an optional resource used to allow direct inbound communication from the internet to an Azure Virtual Machine.
- Network Security Group (NSG): Think of this as a highly granular digital bouncer. A Network Security Group is an optional resource used to filter network traffic entering an Azure Virtual Machine. Equally importantly, a Network Security Group is an optional resource used to filter network traffic leaving an Azure Virtual Machine, protecting against data exfiltration.
