Set up hosts for live migration without Failover Clustering

Applies to: Windows Server 2022, Windows Server 2016, Microsoft Hyper-V Server 2016, Windows Server 2019, Microsoft Hyper-V Server 2019

This article shows you how to set up hosts that aren't clustered so you can do live migrations between them. Use these instructions if you didn't set up live migration when you installed Hyper-V, or if you want to change the settings. To set up clustered hosts, use tools for Failover Clustering.

Requirements for setting up live migration

To set up non-clustered hosts for live migration, you'll need:

  • A user account with permission to perform the various steps. Membership in the local Hyper-V Administrators group or the Administrators group on both the source and destination computers meets this requirement, unless you're configuring constrained delegation. Membership in the Domain Administrators group is required to configure constrained delegation.

  • The Hyper-V role in Windows Server 2016 or Windows Server 2012 R2 installed on the source and destination servers. You can do a live migration between hosts running Windows Server 2016 and Windows Server 2012 R2 if the virtual machine is at least version 5.
    For version upgrade instructions, see Upgrade virtual machine version in Hyper-V on Windows 10 or Windows Server 2016. For installation instructions, see Install the Hyper-V role on Windows Server.

  • Source and destination computers that either belong to the same Active Directory domain, or belong to domains that trust each other.

  • The Hyper-V management tools installed on a computer running Windows Server 2016 or Windows 10, unless the tools are installed on the source or destination server and you'll run the tools from the server.

Consider options for authentication and networking

Consider how you want to set up the following:

  • Authentication: Which protocol will be used to authenticate live migration traffic between the source and destination servers? The choice determines whether you'll need to sign on to the source server before starting a live migration:

    • Kerberos lets you avoid having to sign in to the server, but requires constrained delegation to be set up. See below for instructions.

    • CredSSP lets you avoid configuring constrained delegation, but requires you sign in to the source server. You can do this through a local console session, a Remote Desktop session, or a remote Windows PowerShell session.

      CredSPP requires signing in for situations that might not be obvious. For example, if you sign in to TestServer01 to move a virtual machine to TestServer02, and then want to move the virtual machine back to TestServer01, you'll need to sign in to TestServer02 before you try to move the virtual machine back to TestServer01. If you don't do this, the authentication attempt fails, an error occurs, and the following message is displayed:

      "Virtual machine migration operation failed at migration Source. Failed to establish a connection with host computer name: No credentials are available in the security package 0x8009030E."

  • Performance: Does it make sense to configure performance options? These options can reduce network and CPU usage, as well as make live migrations go faster. Consider your requirements and your infrastructure, and test different configurations to help you decide. The options are described at the end of step 2.

  • Network preference: Will you allow live migration traffic through any available network, or isolate the traffic to specific networks? As a security best practice, we recommend that you isolate the traffic onto trusted, private networks because live migration traffic is not encrypted when it is sent over the network. Network isolation can be achieved through a physically isolated network or through another trusted networking technology such as VLANs.

Upgrading to Windows Server 2025 (preview)


Windows Server 2025 is in PREVIEW. This information relates to a prerelease product that may be substantially modified before it's released. Microsoft makes no warranties, expressed or implied, with respect to the information provided here.

Starting with Windows Server 2025 (preview), Credential Guard is enabled by default on all domain-joined servers that aren't Domain Controllers. As a result you might not be able to use CredSSP-based Live Migration with Hyper-V after upgrading to Windows Server 2025. CredSSP-based delegation is the default for Windows Server 2022 and earlier for live migration. Instead use Kerberos constrained Delegation, as described in the following section. For more information, see Live migration with Hyper-V breaks when upgrading to Windows Server 2025.

Step 1: Configure constrained delegation (optional)

If you have decided to use Kerberos to authenticate live migration traffic, configure constrained delegation using an account that is a member of the Domain Administrators group.

Use the Users and Computers snap-in to configure constrained delegation

  1. Open the Active Directory Users and Computers snap-in. (From Server Manager, select the server if it's not selected, click Tools >> Active Directory Users and Computers).

  2. From the navigation pane in Active Directory Users and Computers, select the domain and double-click the Computers folder.

  3. From the Computers folder, right-click the computer account of the source server and then click Properties.

  4. From Properties, click the Delegation tab.

  5. On the delegation tab, select Trust this computer for delegation to the specified services only and then select Use any authentication protocol.

  6. Click Add.

  7. From Add Services, click Users or Computers.

  8. From Select Users or Computers, type the name of the destination server. Click Check Names to verify it, and then click OK.

  9. From Add Services, in the list of available services, do the following and then click OK:

    • To move virtual machine storage, select cifs. This is required if you want to move the storage along with the virtual machine, as well as if you want to move only a virtual machine's storage. If the server is configured to use SMB storage for Hyper-V, this should already be selected.

    • To move virtual machines, select Microsoft Virtual System Migration Service.

  10. On the Delegation tab of the Properties dialog box, verify that the services you selected in the previous step are listed as the services to which the destination computer can present delegated credentials. Click OK.

  11. From the Computers folder, select the computer account of the destination server and repeat the process. In the Select Users or Computers dialog box, be sure to specify the name of the source server.

The configuration changes take effect after both of the following happen:

  • The changes are replicated to the domain controllers that the servers running Hyper-V are logged into.
  • The domain controller issues a new Kerberos ticket.

Step 2: Set up the source and destination computers for live migration

This step includes choosing options for authentication and networking. As a security best practice, we recommend that you select specific networks to use for live migration traffic, as discussed above. This step also shows you how to choose the performance option.

Use Hyper-V Manager to set up the source and destination computers for live migration

  1. Open Hyper-V Manager. (From Server Manager, click Tools >>Hyper-V Manager.)

  2. In the navigation pane, select one of the servers. (If it isn't listed, right-click Hyper-V Manager, click Connect to Server, type the server name, and click OK. Repeat to add more servers.)

  3. In the Action pane, click Hyper-V Settings >>Live Migrations.

  4. In the Live Migrations pane, check Enable incoming and outgoing live migrations.

  5. Under Simultaneous live migrations, specify a different number if you don't want to use the default of 2.

  6. Under Incoming live migrations, if you want to use specific network connections to accept live migration traffic, click Add to type the IP address information. Otherwise, click Use any available network for live migration. Click OK.

  7. To choose Kerberos and performance options, expand Live Migrations and then select Advanced Features.

    • If you have configured constrained delegation, under Authentication protocol, select Kerberos.
    • Under Performance options, review the details and choose a different option if it's appropriate for your environment.
  8. Click OK.

  9. Select the other server in Hyper-V Manager and repeat the steps.

Use Windows PowerShell to set up the source and destination computers for live migration

Three cmdlets are available for configuring live migration on non-clustered hosts: Enable-VMMigration, Set-VMMigrationNetwork, and Set-VMHost. This example uses all three and does the following:

  • Configures live migration on the local host
  • Allows incoming migration traffic only on a specific network
  • Chooses Kerberos as the authentication protocol

Each line represents a separate command.

PS C:\> Enable-VMMigration

PS C:\> Set-VMMigrationNetwork

PS C:\> Set-VMHost -VirtualMachineMigrationAuthenticationType Kerberos

Set-VMHost also lets you choose a performance option (and many other host settings). For example, to choose SMB but leave the authentication protocol set to the default of CredSSP, type:

PS C:\> Set-VMHost -VirtualMachineMigrationPerformanceOption SMB

This table describes how the performance options work.

Option Description
TCP/IP Copies the memory of the virtual machine to the destination server over a TCP/IP connection.
Compression Compresses the memory content of the virtual machine before copying it to the destination server over a TCP/IP connection. Note: This is the default setting.
SMB Copies the memory of the virtual machine to the destination server over an SMB 3.0 connection.

- SMB Direct is used when the network adapters on the source and destination servers have Remote Direct Memory Access (RDMA) capabilities enabled.
- SMB Multichannel automatically detects and uses multiple connections when a proper SMB Multichannel configuration is identified.

For more information, see Improve Performance of a File Server with SMB Direct.

Next steps

After you set up the hosts, you're ready to do a live migration. For instructions, see Use live migration without Failover Clustering to move a virtual machine.