Image

• A virtual machine image is a template for creating new instances
• Similar to OS Images, a VM Image is a collection of metadata and pointers to a set of Virtual Hard Disks (VHDs)
  • VHD is a virtual space for storing your data or system for your Virtual Machines
  • VHD => stored as page blobs in Azure Storage
• Image captures all the data that virtual machine will include
• Example:
  • OS Image: Windows, Linux
  • Application infrastructure image: Citrix netscaler, Cisco ASA

Network

Network connectivity between internal communications or to the internet.

• When you create an Azure virtual machine (VM), you must create a virtual network (VNet) or use an existing VNet
• You create these resources to support communication with a VM
  • Network interfaces
  • IP addresses
  • Virtual network and subnets
• You can create a VNet before you create a VM or you can as you create a VM

Network interface card

• NIC => Network interface card
• See: Network interface in Azure virtual network

IP address

You can assign Public or Private IP addresses to a NIC in Azure:

• Public IP address: to communicate inbound and outbound (without network address translation (NAT)) with the Internet and other Azure resources not connected to a VNet
• Private IP address:
  • for communication within
    • a VNet
    • on-premises network
    • Internet (with NAT)
  • You must assign at least one private IP address to a VM

Block storage

Virtual machines will have a block storage device associated with it to store the operating system and also additional block storage devices if required for application data.

• Managed storage
• Disk storage

VM Components

• Image (VM image)
• Network (VNet and subnet, NIC, Public IP address)
• Storage (OS disk, Data disk)