Enable replication to Azure for VMware VMs

This article describes how to enable replication of on-premises VMware VMs to Azure.


This article assumes that you have:

  1. Set up on-premises source environment.
  2. Set up target environment in Azure.

Before you start

When replicating VMware virtual machines:

  • Your Azure user account needs to have certain permissions to enable replication of a new virtual machine to Azure.
  • VMware VMs are discovered every 15 minutes. It might take 15 minutes or longer for them to appear in the Azure portal after discovery. Likewise, discovery can take 15 minutes or more when you add a new vCenter server or vSphere host.
  • Environment changes on the virtual machine (such as VMware tools installation) can take 15 minutes or more to be updated in the portal.
  • You can check the last discovered time for VMware VMs in the Last Contact At field for the vCenter server/vSphere host, on the Configuration Servers page.
  • To add machines for replication without waiting for the scheduled discovery, highlight the configuration server (don’t click it), and click the Refresh button.
  • When you enable replication, if the machine is prepared, the process server automatically installs the Mobility Service on it.

Enable replication


  • Azure Site Recovery now replicates directly to Managed Disks for all new replications. Process Server writes replication logs to a cache storage account in target region. These logs are used to create recovery points in replica managed disks.
  • At the time of failover, the recovery point selected by customer is used to create the target managed disk.
  • VMs which are previously configured to replicate to target storage accounts will not be impacted.
  • Replication to storage accounts for a new machine is only available via REST API and Powershell. Use API version 2016-08-10 or 2018-01-10 for replicating to storage accounts.
  1. Click Step 2: Replicate application > Source. After you've enabled replication for the first time, click +Replicate in the vault to enable replication for additional machines.

  2. In the Source page > Source, select the configuration server.

  3. In Machine type, select Virtual Machines or Physical Machines.

  4. In vCenter/vSphere Hypervisor, select the vCenter server that manages the vSphere host, or select the host. This setting isn't relevant if you're replicating physical machines.

  5. Select the process server, which will be the name of the configuration server if you haven't created any additional process servers. Then click OK.

    Enable replication source

  6. In Target, select the subscription and the resource group where you want to create the failed-over virtual machines. Choose the deployment model that you want to use in Azure for the failed-over virtual machines.

  7. Select the Azure network and subnet to which Azure VMs will connect when they're spun up after failover. The network must be in the same region as the Recovery Services vault. Select Configure now for selected machines to apply the network setting to all machines you select for protection. Select Configure later to select the Azure network per machine. If you don't have a network, you need to create one. To create a network by using Resource Manager, click Create new. Select a subnet if applicable, and then click OK.

    Enable replication target setting

  8. In Virtual Machines > Select virtual machines, select each machine you want to replicate. You can only select machines for which replication can be enabled. Then click OK. If you are not able to view/select any particular virtual machine, click here to resolve the issue.

    Enable replication select virtual machines

  9. In Properties > Configure properties, select the account used by the process server to automatically install the Mobility Service on the machine. Also, choose the type of target managed disk that you would want to replicate to based on your data churn patterns.

  10. By default, all disks of a source machine are replicated. To exclude disks from replication, uncheck Include checkbox against any disks you don't want to replicate. Then click OK. You can set additional properties later. Learn more about excluding disks.

    Enable replication configure properties

  11. In Replication settings > Configure replication settings, verify that the correct replication policy is selected. You can modify replication policy settings in Settings > Replication policies > (policy name) > Edit Settings. Changes you apply to a policy also apply to replicating and new machines.

  12. Enable Multi-VM consistency if you want to gather machines into a replication group. Specify a name for the group, and then click OK.


    • Machines in a replication group replicate together and have shared crash-consistent and app-consistent recovery points when they fail over.
    • Gather VMs and physical servers together so that they mirror your workloads. Enabling multi-VM consistency can impact workload performance. Use only if machines are running the same workload and you need consistency.

    Enable replication

  13. Click Enable Replication. You can track progress of the Enable Protection job in Settings > Jobs > Site Recovery Jobs. After the Finalize Protection job runs, the machine is ready for failover.

View and manage VM properties

Next, you verify the properties of the source machine. Remember that the Azure VM name needs to conform with Azure virtual machine requirements.

  1. Click Settings > Replicated items >, and then select the machine. The Essentials page shows information about machine settings and status.
  2. In Properties, you can view replication and failover information for the VM.
  3. In Compute and Network > Compute properties, you can change multiple VM propoerties:
    • Azure VM name - Modify the name to comply with Azure requirements if necessary

    • Target VM size or VM type - The default VM size is chosen based on the source VM size. You can select a different VM size based on the need any time before failover. Note that VM disk size is also based on source disk size and it can only be changed post failover. Learn more on disk sizes and IOPS in our Scalability targets for disks article.

      Compute and Network properties

    • Resource Group - You can select a resource group from which a machine becomes part of a post failover. You can change this setting any time before failover. Post failover, if you migrate the machine to a different resource group, the protection settings for that machine break.

    • Availability Set - You can select an availability set if your machine needs to be part of a post failover. While you're selecting an availability set, keep in mind that:

      • Only availability sets belonging to the specified resource group are listed.
      • Machines with different virtual networks cannot be a part of the same availability set.
      • Only virtual machines of the same size can be a part of an availability set.
  4. You can also view and add information about the target network, subnet, and IP address assigned to the Azure VM.
  5. In Disks, you can see the operating system and data disks on the VM to be replicated.

Configure networks and IP addresses

  • You can set the target IP address. If you don't provide an address, the failed-over machine uses DHCP. If you set an address that isn't available at failover, the failover doesn't work. If the address is available in the test failover network, the same target IP address can be used for test failover.
  • The number of network adapters is dictated by the size you specify for the target virtual machine, as follows:
    • If the number of network adapters on the source machine is less than or equal to the number of adapters allowed for the target machine size, then the target has the same number of adapters as the source.
    • If the number of adapters for the source virtual machine exceeds the number allowed for the target size, then the target size maximum is used. For example, if a source machine has two network adapters and the target machine size supports four, the target machine has two adapters. If the source machine has two adapters but the supported target size only supports one, then the target machine has only one adapter.
    • If the virtual machine has multiple network adapters, they all connect to the same network. Also, the first one shown in the list becomes the Default network adapter in the Azure virtual machine.

Azure Hybrid Benefit

Microsoft Software Assurance customers can use Azure Hybrid Benefit to save on licensing costs for Windows Server machines that are migrated to Azure, or to use Azure for disaster recovery. If you're eligible to use the Azure Hybrid Benefit, you can specify that the virtual machine assigned this benefit is the one Azure Site Recovery creates if there's a failover. To do this:

  • Go to the Compute and Network properties section of the replicated virtual machine.
  • Answer the question that asks if you have a Windows Server License that makes you eligible for Azure Hybrid Benefit.
  • Select the check box to confirm that you have an eligible Windows Server license with Software Assurance, which you can use to apply the Azure Hybrid Benefit on the machine that will be created on failover.
  • Save settings for the replicated machine.

Learn more about Azure Hybrid Benefit.

Common issues

  • Each disk should be less than 4 TB in size.
  • The OS disk should be a basic disk and not a dynamic disk.
  • For generation 2/UEFI-enabled virtual machines, the operating system family should be Windows and the boot disk should be less than 300 GB.

Next steps

After protection is complete and the machine has reached a protected state, you can try a failover to check whether your application comes up in Azure or not.