Creating and deploying a custom image to an Azure virtual machine is an essential skill and task when it comes to the preparation for the AZ-120 Planning and Administering Azure for SAP Workloads exam. In this in-depth discussion, we will explore the steps to create, manage, and deploy a custom image in a Microsoft Azure environment.
1. Creation of a Custom Image
To create a custom image of a virtual machine (VM) in Azure for SAP workloads, start by capturing the image of the entire Azure VM. Here’s a step-by-step guide:
- RDP into the VM.
- Run Sysprep to generalize the VM. Sysprep is located in %windir%\system32\sysprep\sysprep.exe.
- In the Sysprep tool, select Enter System Out-of-Box Experience (OOBE) and tick the Generalize checkbox.
- Choose Shutdown for Shutdown Options and click OK.
- Start PowerShell and connect to Azure using the Connect-AzAccount command.
- Use the New-AzImageConfig command to create an image configuration.
- Use the New-AzImage command to create a new image.
Here is an example of the PowerShell commands:
Connect-AzAccount
$imageConfig = New-AzImageConfig -Location 'East US' -SourceVirtualMachineId '/subscriptions/subscriptionId/resourceGroups/myResourceGroup/providers/Microsoft.Compute/virtualMachines/myVM'
$image = New-AzImage -Image $imageConfig -ImageName 'myImage' -ResourceGroupName 'myResourceGroup'
This script first connects to your Azure account, then creates an image configuration and finally an image from a virtual machine.
2. Deployment of the Custom Image
Once the custom image exists, you can create new VMs based on this image. This can be done through the Azure portal, Azure CLI, or using a template.
Here is the example of a PowerShell command to create a VM from the image:
$cred = Get-Credential -Message "Enter a username and password for the virtual machine."
New-AzVm `
-ResourceGroupName "myResourceGroup" `
-Name "myVM" `
-Location "East US" `
-VirtualNetworkName "myVnet" `
-SubnetName "mySubnet" `
-SecurityGroupName "myNetworkSecurityGroup" `
-PublicIpAddressName "myPublicIpAddress" `
-OpenPorts 80,3389 `
-Credential $cred `
-Image "myImage"
This PowerShell command asks for your credentials, then will set up and deploy your VM in a secure network, opening ports 80 and 3389 for web and RDP traffic, and using the custom image “myImage”.
Deploying custom images to Azure Virtual Machines is a fundamental part of managing SAP workloads in Azure. This hands-on understanding not only prepares you for the AZ-120 examination but also significantly enhances your real-world Azure administration capabilities.
Remember, creating and managing custom images help ensure a standardized and controlled IT environment, which is especially crucial for consistent SAP deployments. Always refer to the Azure documentation for the most reliable and up-to-date information.
Practice Test
Azure allows creating and deploying custom images on virtual machines.
- True
- False
Answer: True
Explanation: Azure has a feature that supports creating and deploying custom images on virtual machines which can be very beneficial especially when setting up environments for specific workloads like SAP.
You can use Azure Portal to create a custom image of Azure virtual machine.
- True
- False
Answer: True
Explanation: The Azure portal provides an option to create a custom image of an Azure VM. It’s a simple process that involves generalizing the VM and then creating an image.
Which of the following is not a step in creating a custom image in Azure VM?
- Generalize the VM
- Deallocate the VM
- Deploy the VM
- Create a managed image
Answer: Deploy the VM
Explanation: Deploying the VM is not a step in creating a custom image. The first three steps are generalizing the VM, deallocating the VM and then creating a managed image.
It is not possible to include data disks in a custom image for Azure VM.
- True
- False
Answer: False
Explanation: It is possible to include both the operating system disks and data disks in a custom image for an Azure VM.
You can deploy a custom image to different Azure subscriptions.
- True
- False
Answer: True
Explanation: Azure allows the deployment of custom image across different subscriptions and even different Azure AD directories.
It is mandatory to use Azure CLI for creating and deploying a custom image to an Azure virtual machine.
- True
- False
Answer: False
Explanation: Azure CLI is not the only way to create and deploy custom images. You can also use Azure Portal, PowerShell and Rest APIs.
You cannot deploy a custom image to a VM that is already running.
- True
- False
Answer: True
Explanation: You need to deallocate VM before you can deploy a custom image to it.
In order to share a custom image across different Azure subscriptions, you should use Azure Shared Image Gallery.
- True
- False
Answer: True
Explanation: Azure Shared Image Gallery is a service that enables you to share your images to different subscriptions.
Which command is used in Azure CLI for generalizing the VM?
- az vm stop
- az vm deallocate
- az vm generalize
- az vm start
Answer: az vm generalize
Explanation: The ‘az vm generalize’ command is used to generalize VM on Azure.
You can create a custom image for Azure VM from a generalized, deallocated VM only.
- True
- False
Answer: True
Explanation: It’s necessary to first generalize and then deallocate the VM before you create a custom image from it.
Managed disks are snapshot based and can be used to create a custom image in Azure.
- True
- False
Answer: True
Explanation: Managed disks in Azure are snapshot based. Simply put, a managed disk is just like a physical disk in an on-premises server but, virtualized.
Azure does not allow creating a custom image from a VM that is in the running state.
- True
- False
Answer: True
Explanation: A virtual machine needs to be in a deallocated state in order to create a custom image.
You can only create Windows custom images in Azure.
- True
- False
Answer: False
Explanation: Azure allows the creation of both Windows and Linux based custom images.
Azure CLI is the only method available to deploy a custom image to an Azure VM.
- True
- False
Answer: False
Explanation: Custom image in Azure VM can be deployed using several methods like Azure portal, Azure CLI, Azure PowerShell, and Azure SDKs.
What should be the state of the VM after generalization process, before creating a custom image?
- Running
- Stopped (deallocated)
- Starting
- None of the above
Answer: Stopped (deallocated)
Explanation: After the VM is generalized, it needs to be stopped (deallocated) before you can create a custom image.
Interview Questions
What is the first step in creating a custom image in Azure?
The first step in creating a custom image in Azure is to prepare the operating system.
How can you prepare an image of a virtual machine in Azure?
You can prepare an image of a virtual machine in Azure by generalizing it. Generalization is the process of removing system-specific data, enabling the image to be reused for new resources.
What command should you use to generalize an approximation of the Azure VM?
You should use the “sysprep” command to generalize an Azure VM approximation.
Why do we need to stop the virtual machine before creating a custom image?
Stopping the VM turns it off and ensures that no pending updates or other changes are written to the disk during the imaging process.
What is the Azure PowerShell command to create a custom image?
The Azure PowerShell command to create a custom image is ‘New-AzImageConfig’.
What role does Azure Portal play in the deployment of a custom image?
Azure Portal provides a user interface for deploying a custom image to a new or existing resource group.
What is the significance of Resource Groups in Azure while deploying a custom image?
Resource groups in Azure are a way to organize and manage resources. They can be used to define deployment boundaries, manage access, and aggregate billing for resources that have the same lifecycle and share a commonality.
After the command ‘New-AzImageConfig’ what is next step to create the image?
After the command ‘New-AzImageConfig’, the next command is ‘New-AzImage’.
Can you use a custom image created in one Azure region in another region?
Yes, you can use a custom image in another Azure region by creating an image version and setting a replication target to the desired region.
What are the benefits of using custom images in Azure?
Custom images in Azure allow you to deploy a group of fully configured services as a single entity, reducing the configuration time and providing more control over VM configurations.
What is the purpose of “sysprep” in custom image creation?
“Sysprep” is used to remove system-specific data from Windows machines. It’s particularly important when creating a custom image that will be used to deploy multiple virtual machines to ensure they’re not identical.
Which operating systems are supported by Azure for custom image creation?
Azure supports numerous operating systems for custom image creation, including multiple versions of Windows Server, Linux, Ubuntu, CentOS, and more.
How command-line interface (CLI) is helpful for creating and deploying custom image to an Azure Virtual Machine?
Azure CLI is a tool that you can use to create, manage, and monitor Azure resources. For creating custom images, you can use CLI commands to automate the process, saving you time and reducing the likelihood of errors.
What are the prerequisites for creating a custom image in Azure?
The prerequisites for creating a custom image in Azure include having an Azure account, having a source virtual machine to create the image from, and ensuring that the VM has been generalized using sysprep (for Windows) or the waagent command (for Linux).
Can I update a custom image after it’s been created?
No, a custom image, once created, cannot be updated. To change the configurations, you will need to create a new image.
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