Creating and Managing Virtual Machines- Part 2

• Structured Summary + Deep Technical Understanding

Primary service:

• Azure Virtual Machines

Related services:

• Azure Virtual Network
• Azure Network Security Group
• Azure Managed Disks
• Nginx

Official documentation:

VM management overview:

Resize VM:

NSG rules:

Move resources:

1️⃣ VM Management Overview#

• Once a VM is deployed, administrators must manage it just like on-premise servers.

Common VM management operations include:

• Authentication and remote access
• Resizing compute resources
• Managing networking
• Managing storage disks
• Installing applications/services
• Diagnostics and monitoring
• Moving resources between environments
• These operations are similar to on-prem virtualization platforms like VMware or Hyper-V but are performed through Azure management tools.

2️⃣ Authentication and Remote Access#

To manage a VM you must connect to it.

Linux VM#

Connection method:

• ssh username@public-ip

Uses:

• SSH keys (recommended)
• Password authentication

Windows VM#

Connection method:

• RDP (Remote Desktop Protocol)

Port:

• 3389

Important concept:

• Remote access requires the correct inbound network rules.

3️⃣ VM Networking Management#

Each VM is connected to:

• Virtual Network
• Subnet
• Network Interface (NIC)
• Optional Public IP

Traffic filtering is controlled using:

• Azure Network Security Group

Example NSG rules:

Example:

• Allow SSH rule to connect to Linux VM.

4️⃣ VM Storage Components#

Azure VMs use:

• Azure Managed Disks

Disk types attached to VM:

OS Disk#

Contains the operating system.

Temporary Disk#

Ephemeral disk used for temporary storage.

Data Disk#

• Used for application data or databases.

Important exam concept:

• Temporary disk data is lost during host migration or restart.

Docs:

5️⃣ Resizing a Virtual Machine#

• One common management task is resizing the VM.

Reasons to resize:

• Increase CPU
• Increase RAM
• Reduce cost
• Handle increased workload

Resize options depend on:

• Region capacity
• VM size family
• Current VM state

Important Behavior#

Resizing may require:

• VM restart
• Temporary downtime
• Stopping the VM to access more size options

Example impact:

• Running services may become unavailable temporarily.

Docs:

6️⃣ VM Deployment Using Azure CLI (Demo)#

VM was created using:

• az vm create

Key parameters used:

• VM name
• Resource group
• OS image
• Security configuration
• SSH key authentication

Example concept:

• If an incorrect image name is used, Azure CLI returns a list of supported images.

7️⃣ SSH Authentication Using Key-Based Access#

After VM creation:

• SSH keys are generated automatically.

Connection command:

• ssh <public-ip>
• Authentication happens using the stored private key in Cloud Shell.

Key advantage:

• More secure than passwords.

8️⃣ Installing Applications on the VM#

After connecting via SSH:

Example commands used:

• sudo apt update
• sudo apt install nginx -y

This installs:

• Nginx

To verify service status:

• sudo systemctl status nginx

9️⃣ Allowing Web Traffic to the VM#

To access the web server:

• An inbound NSG rule must allow HTTP.

Rule created:

• Port: 80
• Protocol: TCP
• Source: Any (for demo purposes)

Once rule applied:

Access via browser:

• http://<public-ip>
• The Nginx default page confirms the web server is running.

🔟 VM Connectivity Troubleshooting#

If SSH fails:

Check:

• 1️⃣ NSG rule allows port 22 2️⃣ VM is running 3️⃣ Public IP exists 4️⃣ VM not currently resizing 5️⃣ Correct username and key

Example issue shown in demo:

• SSH failed temporarily because VM was resizing.

1️⃣1️⃣ Moving a Virtual Machine#

Azure supports moving resources between:

• Resource Groups
• Subscriptions
• Regions (with restrictions)

Important limitation shown:

• VM with Trusted Launch enabled cannot be moved across regions.

Trusted Launch provides:

• Secure Boot
• vTPM protection
• Integrity validation

Docs:

Moving Between Resource Groups#

• Supported operation.

Steps:

• 1️⃣ Select VM and related resources 2️⃣ Choose Move → Move to another resource group 3️⃣ Validate dependencies 4️⃣ Complete move operation

1️⃣2️⃣ VM Architecture Overview#

Typical architecture:

• VM
• │
• ├─ Managed OS Disk
• ├─ Data Disk(s)
• ├─ NIC
• │ ├─ Private IP
• │ └─ Optional Public IP
• │
• └─ Network Security Group

VM runs inside:

• Azure Virtual Network

1️⃣3️⃣ Diagnostics and Monitoring#

VM diagnostic features include:

• Boot diagnostics
• Performance metrics
• Activity logs
• Guest-level diagnostics

These help administrators troubleshoot:

• Boot failures
• Network connectivity
• Resource usage
• Application issues

Docs:

1️⃣4️⃣ Key Exam Concepts#

Important concepts to remember:

✔ VM resizing may require restart ✔ SSH/RDP requires NSG rule ✔ Managed disks store VM data ✔ Temp disk data is not persistent ✔ NSG controls inbound traffic ✔ VM can be resized for performance or cost optimization ✔ Resource moves may have restrictions ✔ Trusted Launch prevents some migration operations

1️⃣5️⃣ Mental Model#

Think of Azure VM management as:

Cloud version of managing a physical server:

• Connect remotely
• Install software
• Adjust hardware resources
• Configure networking
• Secure access
• But Azure handles the underlying infrastructure.

1️⃣6️⃣ Final Takeaways#

• ✔ Azure VMs require ongoing management after deployment ✔ SSH or RDP enables remote administration ✔ NSGs control traffic access ✔ VM resizing helps scale workloads ✔ Applications can be installed directly on the VM ✔ Storage consists of OS, temp, and data disks ✔ Moving VMs has platform limitations ✔ Trusted Launch improves security but limits mobility

If you'd like, I can also show you a **very useful AZ-104 cheat sheet for Azure **VMs, including:

• VM availability sets vs zones
• VM scale sets
• VM pricing optimization
• Bastion vs Public IP access
• Disk performance tiers
• This topic alone accounts for 20–30% of real Azure admin interviews.