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

This sample requires the Azure PowerShell module version 5.1.1 or later. Run Get-Module -ListAvailable AzureRM to find the version. If you need to install or upgrade, see Install Azure PowerShell module.

Run Connect-AzureRmAccount to create a connection with Azure.

If you don't have an Azure subscription, create a 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-AzureRmVMSize -Location westus
$virtualMachineSize = 'Standard_DS3'

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

$snapshot = Get-AzureRmSnapshot -ResourceGroupName $resourceGroupName -SnapshotName $snapshotName
$diskConfig = New-AzureRmDiskConfig -Location $snapshot.Location -SourceResourceId $snapshot.Id -CreateOption Copy
$disk = New-AzureRmDisk -Disk $diskConfig -ResourceGroupName $resourceGroupName -DiskName $osDiskName

#Initialize virtual machine configuration
$VirtualMachine = New-AzureRmVMConfig -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-AzureRmVMOSDisk -VM $VirtualMachine -ManagedDiskId $disk.Id -CreateOption Attach -Linux

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

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

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

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

#Create the virtual machine with Managed Disk
New-AzureRmVM -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-AzureRmResourceGroup -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-AzureRmDisk 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-AzureRmVMConfig 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-AzureRmVMOSDisk Attaches a managed disk using the Id property of the disk as OS disk to a new virtual machine
New-AzureRmPublicIpAddress Creates a public IP address.
New-AzureRmNetworkInterface Creates a network interface.
New-AzureRmVM Create a virtual machine.
Remove-AzureRmResourceGroup Removes a resource group and all resources contained within.

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.