Create a virtual machine using an existing managed OS disk with PowerShell

This script creates a virtual machine by attaching an existing managed disk as OS disk. Use this script in preceding scenarios:

• Create a VM from an existing managed OS disk that was copied from a managed disk in different subscription
• Create a VM from an existing managed disk that was created from a specialized VHD file
• Create a VM from an existing managed OS disk that was created from a snapshot

If you don't have an Azure subscription, create an Azure free account before you begin.

Sample script

#Provide the subscription Id
$subscriptionId = 'yourSubscriptionId'

#Provide the name of your resource group
$resourceGroupName ='yourResourceGroupName'

#Provide the name of the snapshot that will be used to create OS disk
$snapshotName = 'yourSnapshotName'

#Provide the name of the OS disk that will be created using the snapshot
$osDiskName = 'yourOSDiskName'

#Provide the name of an existing virtual network where virtual machine will be created
$virtualNetworkName = 'yourVNETName'

#Provide the name of the virtual machine
$virtualMachineName = 'yourVMName'

#Provide the size of the virtual machine
#e.g. Standard_DS3
#Get all the vm sizes in a region using below script:
#e.g. Get-AzVMSize -Location westus
$virtualMachineSize = 'Standard_DS3'

#Set the context to the subscription Id where Managed Disk will be created
Select-AzSubscription -SubscriptionId $SubscriptionId

$snapshot = Get-AzSnapshot -ResourceGroupName $resourceGroupName -SnapshotName $snapshotName

$diskConfig = New-AzDiskConfig -Location $snapshot.Location -SourceResourceId $snapshot.Id -CreateOption Copy

$disk = New-AzDisk -Disk $diskConfig -ResourceGroupName $resourceGroupName -DiskName $osDiskName

#Initialize virtual machine configuration
$VirtualMachine = New-AzVMConfig -VMName $virtualMachineName -VMSize $virtualMachineSize

#Use the Managed Disk Resource Id to attach it to the virtual machine. Please change the OS type to linux if OS disk has linux OS
$VirtualMachine = Set-AzVMOSDisk -VM $VirtualMachine -ManagedDiskId $disk.Id -CreateOption Attach -Windows

#Create a public IP for the VM
$publicIp = New-AzPublicIpAddress -Name ($VirtualMachineName.ToLower()+'_ip') -ResourceGroupName $resourceGroupName -Location $snapshot.Location -AllocationMethod Dynamic

#Get the virtual network where virtual machine will be hosted
$vnet = Get-AzVirtualNetwork -Name $virtualNetworkName -ResourceGroupName $resourceGroupName

# Create NIC in the first subnet of the virtual network
$nic = New-AzNetworkInterface -Name ($VirtualMachineName.ToLower()+'_nic') -ResourceGroupName $resourceGroupName -Location $snapshot.Location -SubnetId $vnet.Subnets[0].Id -PublicIpAddressId $publicIp.Id

$VirtualMachine = Add-AzVMNetworkInterface -VM $VirtualMachine -Id $nic.Id

#Create the virtual machine with Managed Disk
New-AzVM -VM $VirtualMachine -ResourceGroupName $resourceGroupName -Location $snapshot.Location

Clean up deployment

Run the following command to remove the resource group, VM, and all related resources.

Remove-AzResourceGroup -Name myResourceGroup

Script explanation

This script uses the following commands to get managed disk properties, attach a managed disk to a new VM and create a VM. Each item in the table links to command specific documentation.

Command	Notes
Get-AzDisk	Gets disk object based on the name and the resource group of a disk. Id property of the returned disk object is used to attach the disk to a new VM
New-AzVMConfig	Creates a VM configuration. This configuration includes information such as VM name, operating system, and administrative credentials. The configuration is used during VM creation.
Set-AzVMOSDisk	Attaches a managed disk using the Id property of the disk as OS disk to a new virtual machine
New-AzPublicIpAddress	Creates a public IP address.
New-AzNetworkInterface	Creates a network interface.
New-AzVM	Create a virtual machine.
Remove-AzResourceGroup	Removes a resource group and all resources contained within.

For marketplace images use Set-AzVMPlan to set the plan information.

Set-AzVMPlan -VM $VirtualMachine -Publisher $Publisher -Product $Product -Name $Bame

Next steps

For more information on the Azure PowerShell module, see Azure PowerShell documentation.

Additional virtual machine PowerShell script samples can be found in the Azure Windows VM documentation.