Live migration in Hyper-V 2012 R2 and SCVMM 2012 R2 relies on several technologies and many specific settings. This guide will cover the most common misconfigurations and how to fix them.

For the most part, live migrations in Hyper-V or System Center Virtual Machine Manager (SCVMM) work flawlessly. However, if you are reading this article, your live migrations probably are not going so smoothly. Understanding where the live migration is breaking down is key to troubleshooting the issue quickly. We will start this guide with the actual live migration settings and work our way through common server breakdowns.

Issues with live migration occur mainly because of server misconfigurations but can also result from networking issues. To simplify the networking aspect and to make troubleshooting easier, you can connect two Hyper-V hosts directly and bypass these issues.

The destination computer is not configured to send or receive live migrations of virtual machines.

Start by checking your Hyper-V live migration settings on the source and destination hosts. When these options are left as unconfigured, you may receive an error message stating that the destination computer is not configured to send or receive live migrations of virtual machines.

In Hyper-V Manager, right-click your host, select Hyper-V Settings, and select the Live Migrations option.

Live migration settings in Hyper-V 2012 R2

Live migration settings in Hyper-V 2012 R2

Ensure that Enable incoming and outgoing live migrations is checked. Incoming live migrations, by default, use any available network. For performance and security purposes, many administrators will segment live migration traffic to a dedicated network. If your Hyper-V hosts are configured this way, test the connection between hosts on that network. You can use the –S parameter in the ping command to specify a source address.

Testing a network connection in the live migration network

Testing a network connection in the live migration network

The source host will occasionally report that an error occurred while attempting to contact the Virtual Machine Management service on the destination computer. Ensure that every automatic service is started on both the source and the destination hosts. Specifically, check that the Hyper-V Virtual Machine Management service and the Remote Procedure Call (RPC) service are running. For SCVMM-managed machines, check the System Center Virtual Machine Manager Agent service as well.

Failed to establish a connection with host. No credentials are available in the security package.

Our error here is directly related to an authentication failure. Unfortunately, the issue can be an incorrect authentication protocol setting or improper delegation.

Hyper-V/SCVMM gives you two authentication protocol options: CredSSP and Kerberos. In most cases, you will want to use Kerberos because it allows for broader live migration configurations. This does require that all of your Hyper-V hosts be a part of a domain.

Kerberos selected as the live migration authentication protocol.

Kerberos selected as the live migration authentication protocol

Using Kerberos requires that you first properly configure constrained delegation. Launch Active Directory Users and Computers. Open the properties of your Hyper-V host computer account and select the Delegation tab.

Select the Trust this computer for delegation to specified services only option, select Use Kerberos only, and click Add. Locate the destination computer if you are using Hyper-V. Add the CIFS service and the Microsoft Virtual System Migration service. Do this on each host, and add every potential destination server.

Configuring constrained delegation on a Hyper-V host account

If you are using SCVMM, you only need to add the SCVMM service account and the CIFS service to each host. You can read all about this particular configuration from TechNet.

The virtual machine cannot be moved to the destination computer. 

A rather frustrating error is the generic The virtual machine cannot be moved to the destination computer. This error occurs in both Hyper-V and SCVMM initiated migrations. It has haunted me on several occasions.

At its root, the error points to incompatible hardware configurations across both host servers. In most cases, this is due to different processor types (more specifically, different features between processors being presented to the VM for use). This error can pop up even when processors on both servers are the same make.

To resolve this error, you first have to shut down the VM (which rather removes the benefit of live migration in the first place). Then, you can enable processor compatibility by opening the VM’s properties and navigating to the Processor hardware configuration. The screenshot below shows the Allow migration to a virtual machine host with a different processor version setting in SCVMM.

“Allow migration” box grayed out because VM is not turned off

“Allow migration” box grayed out because VM is not turned off

Very rarely, this error is related to misconfigurations in the vNIC and can be resolved by removing and reinstalling the vNIC hardware. Finally, some report success with live migrations by restarting the destination host and not changing compatibility options.

Hyper-V settings that can break live migrations

The Windows Firewall can also block live migration connections if the default rules are modified or overwritten. Double-check these settings; the Hyper-V and Hyper-V Management Clients rule groups should be enabled on the Hyper-V host servers.

Hyper-V firewall rules in Windows Server 2012 R2

Hyper-V firewall rules in Windows Server 2012 R2

Two common issues with Hyper-V settings occur when resources on the Hyper-V host change during the migration process. If the VM migration starts successfully but fails during the process, you may see this error: There Was an Error During the Move Operation.

The first possible cause occurs when the host is not accounting for changes in memory usage during the migration process. When a host has several VMs that use dynamic memory, a running VM may consume more memory than is available for the running VMs plus the migrated VM. If memory usage is too high, reduce the minimal startup memory for the new VM or the maximum memory for running VMs, or add additional memory to the host.

The second possible cause occurs when the virtual hard disk is migrated but a network outage prevents the live migration from finishing. At this point, you may see an offline VM on the destination host and an online VM on the source host. In SCVMM, you can resolve this inconsistent state by restarting the live migration job. You can also resolve this manually by disconnecting the NIC on the source VM and then starting the new destination VM. When the destination VM is running and operating smoothly, destroy the source VM.

This wraps up our live migration troubleshooting guide for Hyper-V and SCVMM. If you have additional information to add to any of these problems, leave a comment below. If your problem wasn’t addressed, let me know by leaving a question below.

7 Comments
  1. cmos99 6 years ago

    I have encountered a stranger issue migrating machines. Linux VM's move flawlessly however windows VM's throw the generic error above all VM's originate from the same hyper-v host source and are being moved to the same destination Hyper-V hosts are server 2012 R2, Scvmm 2012R2 is being used.

  2. MJ Almassud 5 years ago

    Very nice and thank you very much for that.

     

    really quick, I noticed that when I select more than a VM in VMM 2012 R2, I see the migrate option grayed out and it'll be available if I have a single VM selected.

     

    Is this by design, or do I have something not configured or mess configured?

    Thanks again

  3. Author

    That is by design - to migrate multi VMs at once, SCVMM assumes you have the hosts in a cluster.

  4. Michael Stoica 5 years ago

    Hey Joseph,

    About the Kerberos, as far as I know you need to configure delegation only if the HyperV servers use a SMB3 storage. If not, being domain members is enough.

  5. Author

    Thanks Michael! That is good to know!

  6. Francesco 4 years ago

    Hello and thanks for the guide.

    We have 2 hyper_v clustered hosts on Windows 2012.Sometime live migration fails and i need to restart hyper-v virtual machine management service to succesfully live migrate virtual machines. What could cause this?

    Thanks Francesco

  7. Author

    What is the exact failure error?

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