Managing Azure Virtual Machines

This section covers essential tasks for managing your Azure Virtual Machines (VMs) throughout their lifecycle, from deployment to ongoing operations.

Starting, Stopping, and Deallocating VMs

You can manage the power state of your VMs to control costs and ensure availability.

Start: Initiates a stopped VM, making it available for use. This incurs compute charges.
Stop: Gracefully shuts down a running VM. The OS is powered off, but the VM's disk resources remain allocated. This stops compute charges but disk charges continue.
Stop (Deallocate): Shuts down a running VM and releases the underlying compute resources. This stops both compute and networking charges. It's the recommended way to save costs when a VM is not actively needed.

You can perform these actions using the Azure portal, Azure CLI, or Azure PowerShell.

Azure CLI Example (Deallocate):

az vm deallocate --resource-group MyResourceGroup --name MyVM

Restarting VMs

A restart operation gracefully shuts down and then restarts the VM. This is useful for applying updates or resolving minor issues.

Like stopping a VM, restarting incurs compute charges while the VM is active.

Azure PowerShell Example:

Restart-AzVM -ResourceGroupName "MyResourceGroup" -Name "MyVM"

Resizing VMs

You can change the size of a VM to adjust its CPU, memory, and storage performance. This is crucial for optimizing costs and meeting changing workload demands.

Important: To resize a VM, it must be deallocated first. After resizing, you will need to start the VM again.

Note: Ensure that the target VM size is available in the Azure region where your VM is located. Some VM sizes are not universally available across all regions.

Attaching and Detaching Data Disks

Virtual machines rely on OS disks for the operating system and can have additional data disks attached for storing applications and data. You can attach new or existing data disks to your VM and detach them when no longer needed.

Attaching: Increases storage capacity and allows for data separation.
Detaching: Frees up disk resources. Be cautious, as detaching a disk will make its data inaccessible to the VM.

Considerations for Data Disks:

Choose the appropriate disk type (e.g., Standard HDD, Standard SSD, Premium SSD, Ultra Disk) based on performance and cost requirements.
Understand the maximum number of data disks supported by a VM size.

Managing VM Extensions

VM extensions are small applications that provide post-deployment configuration and management for Azure VMs. They can be used for tasks like configuration management, monitoring, security, and recovery.

Configuration Management: Deploy scripts or use tools like Desired State Configuration (DSC).
Monitoring: Install agents for Azure Monitor or other monitoring solutions.
Security: Deploy antivirus or vulnerability scanning agents.

Tip: Regularly review and update VM extensions to ensure they are functioning correctly and are secured against the latest threats.

VM Snapshots and Images

Creating snapshots and custom images is vital for backup, disaster recovery, and deploying consistent VM configurations.

Snapshots: Point-in-time copies of a disk. They are useful for backing up individual disks before making significant changes.
Custom Images: A copy of a VM's OS disk, optionally including data disks. Custom images allow you to deploy new VMs with pre-installed software and configurations.

Warning: While snapshots are useful, they are not a substitute for a comprehensive backup strategy. Consider Azure Backup for robust data protection.

Connecting to Your VM

Securely connect to your VMs to manage them interactively.

Windows VMs: Use Remote Desktop Protocol (RDP). Ensure RDP port (3389) is open in the network security group and that you have valid credentials.
Linux VMs: Use Secure Shell (SSH). Ensure SSH port (22) is open and use SSH keys or passwords for authentication.

Azure Bastion provides a more secure and seamless RDP/SSH connection experience directly through the Azure portal without exposing public IP addresses.