Tutorial / Cram Notes
Compute Resources
- CPU (Central Processing Unit)
The CPU is the brain of the VM, executing instructions and processing data. In Azure, VM sizes determine the amount of CPU available to a VM. For example, the B-Series offers burstable CPU performance suitable for workloads that do not require continuous CPU use, while the F-Series provides a higher CPU-to-memory ratio for more CPU-intensive applications.
- Memory (RAM)
The Random Access Memory (RAM) is a form of temporary data storage that is directly accessed by the CPU. VM performance can be significantly affected by the amount of allocated memory. Azure VMs offer a range of memory configurations to fit differing requirements.
- VM Size
Azure classifies VMs into series and sizes that indicate the compute, memory, and storage capabilities of a VM. For example, the Dv4 series is designed for general-purpose workloads, while the Ev4 series is optimized for memory-intensive applications.
Storage Resources
- Disk Storage
VMs require disk storage for the operating system, applications, and data. In Azure, you have options like Azure Blob storage for object storage, managed disks for simplified disk management, and Ultra Disks for high-throughput and low-latency workloads.
- Disk Performance
The type of disk (Standard HDD, Standard SSD, Premium SSD, and Ultra Disks) you choose affects the performance of your VM. Premium SSDs are often chosen for I/O intensive applications.
Networking Resources
- Virtual Network (VNet)
VNets enable Azure resources, like VMs, to communicate with each other, the internet, and on-premises networks. It’s essential to configure the VNet and subnets correctly to ensure connectivity and security.
- IP Addresses
VMs can have public IP addresses for internet access and private IP addresses for internal network communication. In an Azure exam context, understanding the difference between static and dynamic IP addressing in Azure is crucial.
- Network Security Groups (NSGs)
NSGs are used to define network security rules that allow or deny inbound and outbound traffic to VMs or subnets. This is key to protecting VMs from unwanted traffic.
Additional Considerations
- Operating System
VMs can run various operating systems such as Windows Server, Linux, or others, depending on the workload needs. Choosing the right operating system is crucial for compatibility and performance.
- Scaling
Understanding the scalability options, such as Azure Virtual Machine Scale Sets, is vital for managing performance and availability during varying load conditions.
- High Availability
For critical workloads, high availability configurations using Availability Sets or Availability Zones can help ensure minimal downtime.
- Management Tools
Tools like Azure Monitor and Azure Automation can help manage VM performance and automate routine tasks, respectively.
- Licensing
Ensuring proper licensing for software used in VMs is crucial from a legal and financial standpoint.
Example VM Configurations
Here’s an example of different Azure VM configurations tailored for various workloads, highlighting the primary resources:
| Series | Purpose | Example VM Size | vCPU | RAM | Disk Options |
|---|---|---|---|---|---|
| B | Cost-effective, burstable workloads | B2s | 2 | 4 GB | Standard HDD/SSD |
| Dv4 | General purpose | D4s_v4 | 4 | 16 GB | Premium SSD |
| Ev4 | Memory-intensive applications | E4s_v4 | 4 | 32 GB | Premium SSD |
| F | Compute-intensive jobs | F4s_v2 | 4 | 8 GB | Premium SSD |
Deploying a VM in Azure requires thoughtful consideration of these resources to balance performance and cost effectively. Azure’s pricing calculator and documentation can help you estimate costs and select the appropriate resources for your VMs as you prepare for the AZ-900 Azure Fundamentals exam.
Practice Test with Explanation
True or False: A virtual machine (VM) in Microsoft Azure requires a user-defined subnet to function.
- False
Azure VMs can be connected to automatically created subnets in Azure Virtual Networks; it is not necessary to have a user-defined subnet for the VM to function.
True or False: Virtual machines in Azure are not dependent on physical hardware.
- True
Virtual machines are an abstraction of physical hardware and are hosted in Microsoft Azure’s data centers, leveraging Azure’s infrastructure.
What type of storage is typically used for Azure virtual machines’ operating system disks?
- [A] Blob storage
- [B] File storage
- [C] Queue storage
- [D] Managed disks
Answer: D
Managed disks are the recommended storage type for Azure virtual machine OS disks due to their high durability, availability, and ease of management.
Which of the following is a required resource when configuring a virtual machine in Azure?
- [A] Virtual Network
- [B] A physical server
- [C] Installation media
- [D] An Azure account
Answer: A
Virtual Network (VNet) is a required resource for Azure VMs as it provides the network environment where the VMs are hosted; a physical server and installation media are not required, and an Azure account is not a VM resource, though you need it to access Azure services.
True or False: You can only create virtual machines in Azure using the Azure portal.
- False
Azure VMs can be created using various methods including the Azure portal, Azure CLI, PowerShell, ARM templates, and SDKs.
How is the size (CPU, RAM, etc.) of a virtual machine in Azure determined?
- [A] By the type of operating system installed
- [B] By the size of the physical server it is hosted on
- [C] By the virtual machine size specification chosen
- [D] By the region where the virtual machine is deployed
Answer: C
The size of an Azure VM is determined by the VM size specification (such as B2s, D2v3) chosen, which specifies the CPU, RAM, and other characteristics.
Which feature can be used to group related resources for an Azure virtual machine, such as networking resources and storage accounts?
- [A] Azure Resource Manager
- [B] Virtual Machine Scale Sets
- [C] Availability Zones
- [D] Resource Groups
Answer: D
Resource Groups are used to group related resources in Azure for easier management and billing purposes.
True or False: Azure virtual machines can be tagged for organizational and billing purposes.
- True
Tags can be applied to Azure virtual machines and other resources to organize and track billing and management across resources.
Can more than one virtual machine share the same virtual network in Azure?
- [A] Yes
- [B] No
Answer: A
Multiple virtual machines can be connected to the same virtual network to allow for communication between VMs.
True or False: Azure Backup is an optional service for protecting data on virtual machines.
- True
Azure Backup is an optional, yet recommended, service that provides backup and recovery solutions for data in Azure VMs.
True or False: Virtual machines in Azure require an internet connection for management and operation purposes.
- False
VMs do not require an internet connection for basic operation; however, an internet connection is necessary for remote management and access unless alternative connectivity options are configured (like VPN or ExpressRoute).
Which of the following can provide scalable storage solutions for Azure virtual machines?
- [A] Azure Blob Storage
- [B] Azure Table Storage
- [C] Azure Queue Storage
- [D] Azure File Storage
Answer: A and D
Azure Blob Storage is used for unstructured data and can be mounted to VMs as VHDs, and Azure File Storage provides SMB-based file shares that can be mounted to VMs. Queue and Table storage are not typically used for VM storage solutions.
Interview Questions
What is a virtual machine (VM)?
A virtual machine (VM) is a software emulation of a computer system.
What is the difference between a VM and a physical machine?
A VM is a software emulation of a computer system, while a physical machine is a tangible computer system.
What are the components of a VM?
The components of a VM include the virtual hard disk, virtual memory, virtual processor, and a virtual network interface.
What is a virtual hard disk?
A virtual hard disk is a file that represents the virtual machine’s hard disk.
What is virtual memory?
Virtual memory is the amount of memory that the virtual machine has access to.
What is a virtual processor?
A virtual processor is a software emulation of a physical CPU.
How does virtual networking work in a VM?
Virtual networking in a VM uses virtual network interfaces to connect to the host computer’s network.
What is a VM image?
A VM image is a preconfigured virtual machine that can be deployed as an instance.
What is the role of a VM agent?
The VM agent is a lightweight process that runs on a VM and provides communication between the VM and the Azure platform.
What is the Azure VM Scale Set?
Azure VM Scale Set is a group of load-balanced virtual machines that can automatically increase or decrease in number based on demand.
How does Azure Backup work with VMs?
Azure Backup provides backup and restore services for VMs, allowing for full VM restores and granular file-level recovery.
What is the Azure VM Boot Diagnostics?
Azure VM Boot Diagnostics provides a screenshot of the VM’s boot-up process to help troubleshoot any issues.
What is the Azure VM serial console?
The Azure VM serial console provides a troubleshooting option for VMs by allowing access to the serial console of a VM.
How does the Azure VM pricing work?
Azure VM pricing is based on factors such as the type of VM, the location, and the usage time.
What is the Azure VM marketplace?
The Azure VM marketplace is a collection of preconfigured VM images and virtual appliances that can be deployed as instances.
Great blog post on the resources required for virtual machines in Azure!
Thanks for the detailed information. It was really helpful!
Can someone explain the importance of VM sizes when creating virtual machines?
I appreciate the breakdown of CPU, memory, and storage resources. Really clarified things for me.
How critical is the network aspect for virtual machines?
Nice explanation! It’s good to know about the different disk types for VMs.
I think the post could use more details on VM scalability options.
Thanks for the post! It helped clear up my doubts regarding VM pricing.