Copy an incremental snapshot to a new region

Incremental snapshots can be copied to any region. The process is managed by Azure, removing the maintenance overhead of managing the copy process by staging a storage account in the target region. Azure ensures that only changes since the last snapshot in the target region are copied to the target region to reduce the data footprint, reducing the recovery point objective. You can check the progress of the copy so you know when a target snapshot is ready to restore disks in the target region. You're only charged for the bandwidth cost of the data transfer across the region and the read transactions on the source snapshots.

This article covers copying an incremental snapshot from one region to another. See Create an incremental snapshot for managed disks for conceptual details on incremental snapshots.

Restrictions

• You can copy 100 incremental snapshots in parallel at the same time per subscription per region.
• If you use the REST API, you must use version 2020-12-01 or newer of the Azure Compute REST API.

Get started

Azure CLI

You can use the Azure CLI to copy an incremental snapshot. You need the latest version of the Azure CLI. See the following articles to learn how to either install or update the Azure CLI.

The following script copies an incremental snapshot from one region to another:

subscriptionId=<yourSubscriptionID>
resourceGroupName=<yourResourceGroupName>
targetSnapshotName=<name>
sourceSnapshotResourceId=<sourceSnapshotResourceId>
targetRegion=<validRegion>

sourceSnapshotId=$(az snapshot show -n $sourceSnapshotName -g $resourceGroupName --query [id] -o tsv)

az snapshot create -g $resourceGroupName -n $targetSnapshotName -l $targetRegion --source $sourceSnapshotId --incremental --copy-start

az snapshot show -n $sourceSnapshotName -g $resourceGroupName --query [completionPercent] -o tsv

Azure PowerShell

You can use the Azure PowerShell module to copy an incremental snapshot. You will need the latest version of the Azure PowerShell module. The following command will either install it or update your existing installation to latest:

Install-Module -Name Az -AllowClobber -Scope CurrentUser

Once that is installed, login to your PowerShell session with Connect-AzAccount.

The following script will copy an incremental snapshot from one region to another.

$subscriptionId="yourSubscriptionIdHere"
$resourceGroupName="yourResourceGroupNameHere"
$sourceSnapshotName="yourSourceSnapshotNameHere"
$targetSnapshotName="yourTargetSnapshotNameHere"
$targetRegion="desiredRegion"

Set-AzContext -Subscription $subscriptionId

$sourceSnapshot=Get-AzSnapshot -ResourceGroupName $resourceGroupName -SnapshotName $sourceSnapshotName

$snapshotconfig = New-AzSnapshotConfig -Location $targetRegion -CreateOption CopyStart -Incremental -SourceResourceId $sourceSnapshot.Id

New-AzSnapshot -ResourceGroupName $resourceGroupName -SnapshotName $targetSnapshotName -Snapshot $snapshotconfig

$targetSnapshot=Get-AzSnapshot -ResourceGroupName $resourceGroupName -SnapshotName $targetSnapshotName

$targetSnapshot.CompletionPercent

Portal

You can also copy an incremental snapshot across regions in the Azure portal. However, you must use this specific link to access the portal, for now: https://aka.ms/incrementalsnapshot

1. Sign in to the Azure portal and navigate to the incremental snapshot you'd like to migrate.

2. Select Copy snapshot.

   

3. For Snapshot type under Instance details select Incremental.

4. Change the Region to the region you'd like to copy the snapshot to.

   

5. Select Review + Create and then Create.

Resource Manager Template

You can also use Azure Resource Manager templates to copy an incremental snapshot. You must use version 2020-12-01 or newer of the Azure Compute REST API. The following snippet is an example of how to copy an incremental snapshot across regions with Resource Manager templates:

{
    "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
    "contentVersion": "1.0.0.0",
    "parameters": {
        "name": {
            "defaultValue": "isnapshot1",
            "type": "String"
        },
        "sourceSnapshotResourceId": {
            "defaultValue": "<your_incremental_snapshot_resource_ID>",
            "type": "String"
        },
        "skuName": {
            "defaultValue": "Standard_LRS",
            "type": "String"
        },
        "targetRegion": {
            "defaultValue": "desired_region",
            "type": "String"
        }
    },
    "variables": {},
    "resources": [
        {
            "type": "Microsoft.Compute/snapshots",
            "sku": {
                "name": "[parameters('skuName')]",
                "tier": "Standard"
            },
            "name": "[parameters('name')]",
            "apiVersion": "2020-12-01",
            "location": "[parameters('targetRegion')]",
            "scale": null,
            "properties": {
                "creationData": {
                    "createOption": "CopyStart",
                    "sourceResourceId": "[parameters('sourceSnapshotResourceId')]"
                },
                "incremental": true
            },
            "dependsOn": []
        }
    ]
}

Next steps

If you'd like to see sample code demonstrating the differential capability of incremental snapshots, using .NET, see Copy Azure Managed Disks backups to another region with differential capability of incremental snapshots.