Azure Virtual Machines (VMs)

Azure VM Architecture:

1. Virtual Machine (VM):
   • Represents a computer system within the Azure cloud.
   • Runs an operating system (Windows or Linux) and applications.
2. Virtual Hard Disk (VHD):
   • The storage for the VM, containing the operating system, applications, and data.
   • Stored in Azure Storage, providing durability and accessibility.
3. Azure Storage:
   • VMs use Azure Storage to store VHDs, providing scalability and redundancy.
4. Azure Networking:
   • VMs are part of a virtual network, enabling communication with other Azure resources and on-premises networks.
   • Azure Load Balancer can distribute incoming network traffic across multiple VM instances.
5. Availability Sets:
   • Organizes VMs to provide high availability.
   • Distributes VMs across multiple physical servers to minimize the impact of hardware failures.
6. Scale Sets:
   • Enables automatic scaling of VM instances based on demand.
7. Managed Disks:
   • Simplifies disk management by handling the storage accounts associated with VM disks.

Azure VM Configuration Examples:

1. Creating a VM in the Azure Portal:

• Go to the Azure Portal.
• Click on "Create a resource" > "Compute" > "Virtual machine."
• Configure settings like subscription, resource group, region, VM name, OS, etc.
• Choose a size based on your resource requirements.
• Configure networking settings, including virtual network and subnet.
• Set up storage options, either using managed disks or unmanaged disks.
• Review and create the VM.

2. Creating a VM using Azure CLI:

    
az group create --name MyResourceGroup --location eastus

az vm create \
  --resource-group MyResourceGroup \
  --name MyVM \
  --image UbuntuLTS \
  --admin-username azureuser \
  --admin-password Password123! \
  --size Standard_DS1_v2
    
    

3. Configuring Network Security Groups (NSG):

• Define inbound and outbound rules to control traffic to and from the VM.
• Example using Azure CLI:

    
az network nsg create --resource-group MyResourceGroup --name MyNSG

az network nsg rule create \
  --resource-group MyResourceGroup \
  --nsg-name MyNSG \
  --name AllowSSH \
  --priority 100 \
  --protocol tcp \
  --destination-port-range 22 \
  --access allow
    
    

4. Scaling VMs with Azure Virtual Machine Scale Sets:

• Create a scale set:

    
az vmss create \
  --resource-group MyResourceGroup \
  --name MyScaleSet \
  --image UbuntuLTS \
  --upgrade-policy-mode automatic \
  --admin-username azureuser \
  --admin-password Password123! \
  --instance-count 3
    
    

• Enable autoscaling:

    
az vmss update \
  --resource-group MyResourceGroup \
  --name MyScaleSet \
  --set virtualMachineProfile.scaleInPolicy.deploymentMinimumInstanceCount=1 \
  --set virtualMachineProfile.scaleInPolicy.deploymentMaximumInstanceCount=5