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Upload a VHD to Azure or copy a managed disk to another region - Azure PowerShell

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Applies to: ✔️ Windows VMs

This article explains how to either upload a VHD from your local machine to an Azure managed disk or copy a managed disk to another region, using the Azure PowerShell module. The process of uploading a managed disk, also known as direct upload, enables you to upload a VHD up to 32 TiB in size directly into a managed disk. Currently, direct upload is supported for Ultra Disks, Premium SSD v2, Premium SSD, Standard SSD, and Standard HDD.

If you're providing a backup solution for IaaS VMs in Azure, you should use direct upload to restore customer backups to managed disks. When uploading a VHD from a source external to Azure, speeds depend on your local bandwidth. When uploading or copying from an Azure VM, your bandwidth would be the same as standard HDDs.

Secure uploads with Microsoft Entra ID

If you're using Microsoft Entra ID to control resource access, you can now use it to restrict uploading of Azure managed disks. This feature is available as a GA offering in all regions. When a user attempts to upload a disk, Azure validates the identity of the requesting user in Microsoft Entra ID, and confirms that user has the required permissions. At a higher level, a system administrator could set a policy at the Azure account or subscription level to ensure that a Microsoft Entra identity has the necessary permissions for uploading before allowing a disk or a disk snapshot to be uploaded. If you have any questions on securing uploads with Microsoft Entra ID, reach out to this email: azuredisks@microsoft .com

Prerequisites

Restrictions

  • VHDs can't be uploaded to empty snapshots.
  • Azure Backup doesn't currently support disks secured with Microsoft Entra ID.
  • Azure Site Recovery doesn't currently support disks secured with Microsoft Entra ID.

Assign RBAC role

To access managed disks secured with Microsoft Entra ID, the requesting user must have either the Data Operator for Managed Disks role, or a custom role with the following permissions:

  • Microsoft.Compute/disks/download/action
  • Microsoft.Compute/disks/upload/action
  • Microsoft.Compute/snapshots/download/action
  • Microsoft.Compute/snapshots/upload/action

For detailed steps on assigning a role, see Assign Azure roles using Azure PowerShell. To create or update a custom role, see Create or update Azure custom roles using Azure PowerShell.

Get started

There are two ways you can upload a VHD with the Azure PowerShell module: You can either use the Add-AzVHD command, which will automate most of the process for you, or you can perform the upload manually with AzCopy.

For Premium SSDs, Standard SSDs, and Standard HDDs, you should generally use Add-AzVHD. However, if you're uploading to an Ultra Disk, or a Premium SSD v2, or if you need to upload a VHD that is larger than 50 GiB, you must upload the VHD or VHDX manually with AzCopy. VHDs 50 GiB and larger upload faster using AzCopy and Add-AzVhd doesn't currently support uploading to an Ultra Disk or a Premium SSD v2.

For guidance on how to copy a managed disk from one region to another, see Copy a managed disk.

Use Add-AzVHD

Prerequisites

Upload a VHD

(Optional) Grant access to the disk

If Microsoft Entra ID is used to enforce upload restrictions on a subscription or at the account level, Add-AzVHD only succeeds if attempted by a user that has the appropriate RBAC role or necessary permissions. You'll need to assign RBAC permissions to grant access to the disk and generate a writeable SAS.

New-AzRoleAssignment -SignInName <emailOrUserprincipalname> `
-RoleDefinitionName "Data Operator for Managed Disks" `
-Scope /subscriptions/<subscriptionId>

Use Add-AzVHD

The following example uploads a VHD from your local machine to a new Azure managed disk using Add-AzVHD. Replace <your-filepath-here>, <your-resource-group-name>,<desired-region>, and <desired-managed-disk-name> with your parameters:

Note

If you're using Microsoft Entra ID to enforce upload restrictions, add DataAccessAuthMode 'AzureActiveDirectory' to the end of your Add-AzVhd command.

# Required parameters
$path = <your-filepath-here>.vhd
$resourceGroup = <your-resource-group-name>
$location = <desired-region>
$name = <desired-managed-disk-name>

# Optional parameters
# $Zone = <desired-zone>
# $sku=<desired-SKU>
# -DataAccessAuthMode 'AzureActiveDirectory'
# -DiskHyperVGeneration = V1 or V2. This applies only to OS disks.

# To use $Zone or #sku, add -Zone or -DiskSKU parameters to the command
Add-AzVhd -LocalFilePath $path -ResourceGroupName $resourceGroup -Location $location -DiskName $name

Manual upload

Prerequisites

To upload your VHD to Azure, you'll need to create an empty managed disk that is configured for this upload process. Before you create one, there's some additional information you should know about these disks.

This kind of managed disk has two unique states:

  • ReadyToUpload, which means the disk is ready to receive an upload but, no secure access signature (SAS) has been generated.
  • ActiveUpload, which means that the disk is ready to receive an upload and the SAS has been generated.

Note

While in either of these states, the managed disk will be billed at standard HDD pricing, regardless of the actual type of disk. For example, a P10 will be billed as an S10. This will be true until revoke-access is called on the managed disk, which is required in order to attach the disk to a VM.

Create an empty managed disk

Before you can create an empty standard HDD for uploading, you'll need the file size of the VHD you want to upload, in bytes. The example code will get that for you but, to do it yourself you can use: $vhdSizeBytes = (Get-Item "<fullFilePathHere>").length. This value is used when specifying the -UploadSizeInBytes parameter.

Now, on your local shell, create an empty standard HDD for uploading by specifying the Upload setting in the -CreateOption parameter as well as the -UploadSizeInBytes parameter in the New-AzDiskConfig cmdlet. Then call New-AzDisk to create the disk.

Replace <yourdiskname>, <yourresourcegroupname>, and <yourregion> then run the following commands:

Important

If you're creating an OS disk, add -HyperVGeneration '<yourGeneration>' to New-AzDiskConfig.

If you're using Microsoft Entra ID to secure your uploads, add -dataAccessAuthMode 'AzureActiveDirectory' to New-AzDiskConfig.
When uploading to an Ultra Disk or Premium SSD v2 you need to select the correct sector size of the target disk. If you're using a VHDX file with a 4k logical sector size, the target disk must be set to 4k. If you're using a VHD file with a 512 logical sector size, the target disk must be set to 512.

VHDX files with logical sector size of 512k aren't supported.

$vhdSizeBytes = (Get-Item "<fullFilePathHere>").length

## For Ultra Disks or Premium SSD v2, add -LogicalSectorSize and specify either 4096 or 512, depending on if you're using a VHDX or a VHD

$diskconfig = New-AzDiskConfig -SkuName 'Standard_LRS' -OsType 'Windows' -UploadSizeInBytes $vhdSizeBytes -Location '<yourregion>' -CreateOption 'Upload'

New-AzDisk -ResourceGroupName '<yourresourcegroupname>' -DiskName '<yourdiskname>' -Disk $diskconfig

If you would like to upload a different disk type, replace Standard_LRS with Premium_LRS, Premium_ZRS, StandardSSD_ZRS, StandardSSD_LRS, or UltraSSD_LRS.

Generate writeable SAS

Now that you've created an empty managed disk that is configured for the upload process, you can upload a VHD to it. To upload a VHD to the disk, you'll need a writeable SAS, so that you can reference it as the destination for your upload.

To generate a writable SAS of your empty managed disk, replace <yourdiskname>and <yourresourcegroupname>, then use the following commands:

$diskSas = Grant-AzDiskAccess -ResourceGroupName '<yourresourcegroupname>' -DiskName '<yourdiskname>' -DurationInSecond 86400 -Access 'Write'

$disk = Get-AzDisk -ResourceGroupName '<yourresourcegroupname>' -DiskName '<yourdiskname>'

Upload a VHD or VHDX

Now that you have a SAS for your empty managed disk, you can use it to set your managed disk as the destination for your upload command.

Use AzCopy v10 to upload your local VHD or VHDX file to a managed disk by specifying the SAS URI you generated.

This upload has the same throughput as the equivalent standard HDD. For example, if you have a size that equates to S4, you will have a throughput of up to 60 MiB/s. But, if you have a size that equates to S70, you will have a throughput of up to 500 MiB/s.

AzCopy.exe copy "c:\somewhere\mydisk.vhd" $diskSas.AccessSAS --blob-type PageBlob

After the upload is complete, and you no longer need to write any more data to the disk, revoke the SAS. Revoking the SAS will change the state of the managed disk and allow you to attach the disk to a VM.

Replace <yourdiskname>and <yourresourcegroupname>, then run the following command:

Revoke-AzDiskAccess -ResourceGroupName '<yourresourcegroupname>' -DiskName '<yourdiskname>'

Copy a managed disk

Direct upload also simplifies the process of copying a managed disk. You can either copy within the same region or copy your managed disk to another region.

The following script will do this for you, the process is similar to the steps described earlier, with some differences, since you're working with an existing disk.

Important

You must add an offset of 512 when you're providing the disk size in bytes of a managed disk from Azure. This is because Azure omits the footer when returning the disk size. The copy will fail if you don't do this. The following script already does this for you.

Replace the <sourceResourceGroupHere>, <sourceDiskNameHere>, <targetDiskNameHere>, <targetResourceGroupHere>, <yourOSTypeHere> and <yourTargetLocationHere> (an example of a location value would be uswest2) with your values, then run the following script in order to copy a managed disk.

Tip

If you are creating an OS disk, add -HyperVGeneration '<yourGeneration>' to New-AzDiskConfig.


$sourceRG = <sourceResourceGroupHere>
$sourceDiskName = <sourceDiskNameHere>
$targetDiskName = <targetDiskNameHere>
$targetRG = <targetResourceGroupHere>
$targetLocate = <yourTargetLocationHere>
$targetVmGeneration = "V1" # either V1 or V2
#Expected value for OS is either "Windows" or "Linux"
$targetOS = <yourOSTypeHere>

$sourceDisk = Get-AzDisk -ResourceGroupName $sourceRG -DiskName $sourceDiskName

# Adding the sizeInBytes with the 512 offset, and the -Upload flag
$targetDiskconfig = New-AzDiskConfig -SkuName 'Standard_LRS' -osType $targetOS -UploadSizeInBytes $($sourceDisk.DiskSizeBytes+512) -Location $targetLocate -CreateOption 'Upload' -HyperVGeneration $targetVmGeneration

$targetDisk = New-AzDisk -ResourceGroupName $targetRG -DiskName $targetDiskName -Disk $targetDiskconfig

$sourceDiskSas = Grant-AzDiskAccess -ResourceGroupName $sourceRG -DiskName $sourceDiskName -DurationInSecond 86400 -Access 'Read'

$targetDiskSas = Grant-AzDiskAccess -ResourceGroupName $targetRG -DiskName $targetDiskName -DurationInSecond 86400 -Access 'Write'

azcopy copy $sourceDiskSas.AccessSAS $targetDiskSas.AccessSAS --blob-type PageBlob

Revoke-AzDiskAccess -ResourceGroupName $sourceRG -DiskName $sourceDiskName

Revoke-AzDiskAccess -ResourceGroupName $targetRG -DiskName $targetDiskName

Next steps

Now that you've successfully uploaded a VHD to a managed disk, you can attach your disk to a VM and begin using it.

To learn how to attach a data disk to a VM, see our article on the subject: Attach a data disk to a Windows VM with PowerShell. To use the disk as the OS disk, see Create a Windows VM from a specialized disk.

If you've additional questions, see the section on uploading a managed disk in the FAQ.