Upload and create a Linux VM from custom disk with the Azure CLI

This article shows you how to upload a virtual hard disk (VHD) to an Azure storage account with the Azure CLI and create Linux VMs from this custom disk. This functionality allows you to install and configure a Linux distro to your requirements and then use that VHD to quickly create Azure virtual machines (VMs).

This topic uses storage accounts for the final VHDs, but you can also do these steps using managed disks.

Quick commands

If you need to quickly accomplish the task, the following section details the base commands to upload a VHD to Azure. More detailed information and context for each step can be found the rest of the document, starting here.

Make sure that you have the latest Azure CLI installed and logged in to an Azure account using az login.

In the following examples, replace example parameter names with your own values. Example parameter names included myResourceGroup, mystorageaccount, and mydisks.

First, create a resource group with az group create. The following example creates a resource group named myResourceGroup in the WestUs location:

az group create --name myResourceGroup --location westus

Create a storage account to hold your virtual disks with az storage account create. The following example creates a storage account named mystorageaccount:

az storage account create --resource-group myResourceGroup --location westus \
  --name mystorageaccount --kind Storage --sku Standard_LRS

List the access keys for your storage account with az storage account keys list. Make a note of key1:

az storage account keys list --resource-group myResourceGroup --account-name mystorageaccount

Create a container within your storage account using the storage key you obtained with az storage container create. The following example creates a container named mydisks using the storage key value from key1:

az storage container create --account-name mystorageaccount \
    --account-key key1 --name mydisks

Finally, upload your VHD to the container you created with az storage blob upload. Specify the local path to your VHD under /path/to/disk/mydisk.vhd:

az storage blob upload --account-name mystorageaccount \
    --account-key key1 --container-name mydisks --type page \
    --file /path/to/disk/mydisk.vhd --name myDisk.vhd

Specify the URI to your disk (--image) with az vm create. The following example creates a VM named myVM using the virtual disk previously uploaded:

az vm create --resource-group myResourceGroup --location westus \
    --name myVM --storage-account mystorageaccount --os-type linux \
    --admin-username azureuser --ssh-key-value ~/.ssh/id_rsa.pub \
    --image https://mystorageaccount.blob.core.windows.net/mydisk/myDisks.vhd \
    --use-unmanaged-disk

The destination storage account has to be the same as where you uploaded your virtual disk to. You also need to specify, or answer prompts for, all the additional parameters required by the az vm create command such as virtual network, public IP address, username, and SSH keys. You can read more about the available classic CLI Resource Manager parameters.

Requirements

To complete the following steps, you need:

• Linux operating system installed in a .vhd file - Install an Azure-endorsed Linux distribution (or see information for non-endorsed distributions) to a virtual disk in the VHD format. Multiple tools exist to create a VM and VHD:
  • Install and configure QEMU or KVM, taking care to use VHD as your image format. If needed, you can convert an image using qemu-img convert.
  • You can also use Hyper-V on Windows 10 or on Windows Server 2012/2012 R2.

• VMs created from your custom disk must reside in the same storage account as the disk itself
  • Create a storage account and container to hold both your custom disk and created VMs
  • After you have created all your VMs, you can safely delete your disk

Make sure that you have the latest Azure CLI installed and logged in to an Azure account using az login.

In the following examples, replace example parameter names with your own values. Example parameter names included myResourceGroup, mystorageaccount, and mydisks.

Prepare the disk to be uploaded

Azure supports various Linux distributions (see Endorsed Distributions). The following articles guide you through how to prepare the various Linux distributions that are supported on Azure:

• CentOS-based Distributions
• Debian Linux
• Oracle Linux
• Red Hat Enterprise Linux
• SLES & openSUSE
• Ubuntu
• Other - Non-Endorsed Distributions

Also see the Linux Installation Notes for more general tips on preparing Linux images for Azure.

Create a resource group

Resource groups logically bring together all the Azure resources to support your virtual machines, such as the virtual networking and storage. For more information resource groups, see resource groups overview. Before uploading your custom disk and creating VMs, you first need to create a resource group with az group create.

The following example creates a resource group named myResourceGroup in the westus location:

az group create --name myResourceGroup --location westus

Create a storage account

Create a storage account for your custom disk and VMs with az storage account create. Any VMs with unmanaged disks that you create from your custom disk need to be in the same storage account as that disk.

The following example creates a storage account named mystorageaccount in the resource group previously created:

az storage account create --resource-group myResourceGroup --location westus \
  --name mystorageaccount --kind Storage --sku Standard_LRS

List storage account keys

Azure generates two 512-bit access keys for each storage account. These access keys are used when authenticating to the storage account, such as to carry out write operations. For more information about storage account access keys, see Manage storage account access keys. You view the access keys with az storage account keys list.

View the access keys for the storage account you created:

az storage account keys list --resource-group myResourceGroup --account-name mystorageaccount

The output is similar to:

info:    Executing command storage account keys list
+ Getting storage account keys
data:    Name  Key                                                                                       Permissions
data:    ----  ----------------------------------------------------------------------------------------  -----------
data:    key1  d4XAvZzlGAgWdvhlWfkZ9q4k9bYZkXkuPCJ15NTsQOeDeowCDAdB80r9zA/tUINApdSGQ94H9zkszYyxpe8erw==  Full
data:    key2  Ww0T7g4UyYLaBnLYcxIOTVziGAAHvU+wpwuPvK4ZG0CDFwu/mAxS/YYvAQGHocq1w7/3HcalbnfxtFdqoXOw8g==  Full
info:    storage account keys list command OK

Make a note of key1 as you will use it to interact with your storage account in the next steps.

Create a storage container

In the same way that you create different directories to logically organize your local file system, you create containers within a storage account to organize your disks. A storage account can contain any number of containers. Create a container with az storage container create.

The following example creates a container named mydisks:

az storage container create \
    --account-name mystorageaccount \
    --name mydisks

Upload VHD

Now upload your custom disk with az storage blob upload. You upload and store your custom disk as a page blob.

Specify your access key, the container you created in the previous step, and then the path to the custom disk on your local computer:

az storage blob upload --account-name mystorageaccount \
    --account-key key1 --container-name mydisks --type page \
    --file /path/to/disk/mydisk.vhd --name myDisk.vhd

Create the VM

To create a VM with unmanaged disks, specify the URI to your disk (--image) with az vm create. The following example creates a VM named myVM using the virtual disk previously uploaded:

You specify the --image parameter with az vm create to point to your custom disk. Ensure that --storage-account matches the storage account where your custom disk is stored. You do not have to use the same container as the custom disk to store your VMs. Make sure to create any additional containers in the same way as the earlier steps before uploading your custom disk.

The following example creates a VM named myVM from your custom disk:

az vm create --resource-group myResourceGroup --location westus \
    --name myVM --storage-account mystorageaccount --os-type linux \
    --admin-username azureuser --ssh-key-value ~/.ssh/id_rsa.pub \
    --image https://mystorageaccount.blob.core.windows.net/mydisks/myDisk.vhd \
    --use-unmanaged-disk

You still need to specify, or answer prompts for, all the additional parameters required by the az vm create command such as username and SSH keys.

Resource Manager template

Azure Resource Manager templates are JavaScript Object Notation (JSON) files that define the environment you wish to build. The templates are broken down in to different resource providers such as compute or network. You can use existing templates or write your own. Read more about using Resource Manager and templates.

Within the Microsoft.Compute/virtualMachines provider of your template, you have a storageProfile node that contains the configuration details for your VM. The two main parameters to edit are the image and vhd URIs that point to your custom disk and your new VM's virtual disk. The following shows an example of the JSON for using a custom disk:

"storageProfile": {
          "osDisk": {
            "name": "myVM",
            "osType": "Linux",
            "caching": "ReadWrite",
            "createOption": "FromImage",
            "image": {
              "uri": "https://mystorageaccount.blob.core.windows.net/mydisks/myDisk.vhd"
            },
            "vhd": {
              "uri": "https://mystorageaccount.blob.core.windows.net/vhds/newvmname.vhd"
            }
          }

You can use this existing template to create a VM from a custom image or read about creating your own Azure Resource Manager templates.

Once you have a template configured, use az group deployment create to create your VMs. Specify the URI of your JSON template with the --template-uri parameter:

az group deployment create --resource-group myNewResourceGroup \
  --template-uri https://uri.to.template/mytemplate.json

If you have a JSON file stored locally on your computer, you can use the --template-file parameter instead:

az group deployment create --resource-group myNewResourceGroup \
  --template-file /path/to/mytemplate.json

Next steps

After you have prepared and uploaded your custom virtual disk, you can read more about using Resource Manager and templates. You may also want to add a data disk to your new VMs. If you have applications running on your VMs that you need to access, be sure to open ports and endpoints.