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

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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 a trial account before you begin.

Prerequisites

  • If you prefer to run CLI reference commands locally, install the Azure CLI. If you're running on Windows or macOS, consider running Azure CLI in a Docker container. For more information, see How to run the Azure CLI in a Docker container.

    • If you're using a local installation, sign in to the Azure CLI by using the az login command. To finish the authentication process, follow the steps displayed in your terminal. For other sign-in options, see Sign in with the Azure CLI.

    • When you're prompted, install the Azure CLI extension on first use. For more information about extensions, see Use extensions with the Azure CLI.

    • Run az version to find the version and dependent libraries that are installed. To upgrade to the latest version, run az upgrade.

Sample script

Sign in to Azure

Use the following script to sign in using a different subscription, replacing <Subscription ID> with your Azure Subscription ID. If you don't have an Azure trial subscription, create an Azure trial subscription before you begin. 

az cloud set -n AzureChinaCloud
az login

subscription="<subscriptionId>" # add subscription here

az account set -s $subscription # ...or use 'az login'

For more information, see set active subscription or log in.

Run the script

# Verified per Raman Kumar as of 2/23/2022

# <FullScript>
#Provide the subscription Id
subscriptionId="<subscriptionId>"

#Provide the name of your resource group
resourceGroupName=myResourceGroupName

#Provide the name of the Managed Disk
managedDiskName=myDiskName

#Provide the OS type
osType=linux

#Provide the name of the virtual machine
virtualMachineName=myVirtualMachineName123

#Set the context to the subscription Id where Managed Disk exists and where VM will be created
az account set --subscription $subscriptionId

#Get the resource Id of the managed disk
managedDiskId=$(az disk show --name $managedDiskName --resource-group $resourceGroupName --query [id] -o tsv)

#Create VM by attaching existing managed disks as OS
az vm create --name $virtualMachineName --resource-group $resourceGroupName --attach-os-disk $managedDiskId --os-type $osType
# </FullScript>

Clean up resources

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

az group delete --name myResourceGroupName

Sample reference

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
az disk show Gets managed disk properties using disk name and resource group name. Id property is used to attach a managed disk to a new VM
az vm create Creates a VM using a managed OS disk

Next steps

For more information on the Azure CLI, see Azure CLI documentation.

Additional virtual machine CLI script samples can be found in the Azure Linux VM documentation.