Managing Hyper-V Virtual Machines

Applies To: Virtual Machine Manager 2008, Virtual Machine Manager 2008 R2, Virtual Machine Manager 2008 R2 SP1

Did you know that System Center 2012 is available? System Center 2012 offers you a single, flexible platform to manage traditional datacenters, private and public clouds, and client computers and devices. Learn more about System Center 2012.

System Center Virtual Machine Manager (VMM) 2008 provides a unified management interface across multiple virtualization software environments, including Hyper-V. VMM abstracts the differences between hypervisor APIs and allows you to run an action without worrying about the virtualization software on which the virtual machine is running. This topic describes considerations specific to creating and managing virtual machines on Hyper-V virtualization software.

With VMM 2008, you can create and manage virtual machines running on Hyper-V hosts. If you add a host that is running Windows Server 2008 and it does not have Hyper-V enabled, VMM 2008 will automatically enable the Hyper-V role on the host for you.


Enabling the Hyper-V role will require a restart.

Introduction to Hyper-V

Hyper-V is a hypervisor-based virtualization platform that Microsoft includes with Windows Server 2008. Unlike Virtual Server 2005 R2, which is a hosted technology running on top of the Windows Server 2003 operating system, Hyper-V runs directly on the system hardware. Hyper-V can run on a full Windows Server 2008 installation or it can run on a minimal Server Core installation for maximum performance with minimal overhead and a relatively small attack surface. Hyper-V requires a 64-bit host and provides support for 32-bit and 64-bit guest virtual machines.

For more information about Hyper-V, visit the Hyper-V forum ( on Microsoft TechNet.

For more information about the guest operating systems supported by Hyper-V, see Supported Operating Systems for Virtual Machines.

Creating Hyper-V Virtual Machines

In Virtual Machine Manager (VMM), you can create new virtual machines from any of the following sources:

  • Existing virtual hard disks (VHDs)

  • Blank virtual hard disks

  • Templates

  • Existing virtual machines

    • Hyper-V virtual machines

    • Virtual Server virtual machines

    • VMware virtual machines

For more information, see Sources of New Virtual Machines.

Important Considerations When Creating Hyper-V Virtual Machines

Consider the following when creating a new Hyper-V virtual machine:

  • To enable Hyper-V virtual machines to share ISO images that are stored in the VMM library, the VMM service account must be a domain account. That account and the machine account for each Hyper-V host must have the required share and NTFS permissions on the library shares, and the server running Hyper-V must be configured for constrained delegation. For procedures, see How to Enable Shared ISO Images for Hyper-V Virtual Machines in VMM.

  • In VMM 2008, use of a shared ISO image file is not supported for self-service users. Instead, VMM attached a copy of the ISO image file to the new virtual machine. VMM 2008 R2 supports shared ISO images for self-service.

  • Hyper-V virtual machine names cannot contain the “:” character.

  • Do not erase text in the Notes field in the Hyper-V Manager user interface. VMM uses the Notes field to track virtual machines.

Converting Virtual Machines to Hyper-V

System Center Virtual Machine Manager (VMM) 2008 allows you to convert existing virtual machines to Hyper-V virtual machines. For example, VMM can copy existing VMware virtual machines and create Hyper-V virtual machines. VMM can also migrate existing Virtual Server virtual machines to a Hyper-V host.

Considerations When Converting VMware Virtual Machines

Virtual-to-virtual (V2V) machine conversion is a read-only operation that does not delete or affect the original source virtual machine. In VMM 2008, depending on the location of the VMware virtual machine, you can perform a V2V conversion in the following ways:

  • Directly from an ESX host

  • From the VMM library

  • From a Windows or Network File System (NFS) share


The host server cannot be in a perimeter network (also known as a screened subnet) where the firewalls or IPsec settings prohibit communication.

For more information, see V2V: Converting Virtual Machines in VMM.

Considerations When Migrating Virtual Server Virtual Machines

In VMM, you can migrate virtual machines between hosts that are using the same virtualization platform. You can also migrate virtual machines from Virtual Server to Hyper-V. When migrating virtual machines, you should consider the following factors:

  • Virtual Server and Hyper-V use the same virtual hard disk (VHD) format.

  • When you migrate a virtual machine from a Virtual Server host to a Hyper-V host in VMM 2008 or VMM 2008 R2, VMM automatically replaces VM Additions version 13.813 or later with Hyper-V Integration Components. Earlier VM Additions versions must be removed manually before migrating the virtual machine; if you remove VM Additions before migrating those virtual machine to Hyper-V, VMM installs Integration Components during the migration.

  • Migrating to Hyper-V will provide additional hardware capabilities. For example, the available RAM will increase from 3.7 GB to 64 GB. For more information, see Supported Hardware Capabilities.

  • VMM uses VMConnect to connect to the console of a Hyper-V virtual machine.

  • VMM checkpoints use snapshots in Hyper-V and differencing disks in Virtual Server. Before you migrate a virtual machine from Virtual Server host to Hyper-V host, you must merge or delete all checkpoints for the virtual machine. If checkpoints are present, VMM blocks the migration.

  • VMM automatically installs Hyper-V Integration Components during the V2V process.

For more information, see How to Migrate a Virtual Machine.

Additional Considerations When Migrating a Virtual Machine with Checkpoints

The following restrictions also apply when you attempt to migrate a virtual machine that has checkpoints:

  • You must delete or merge all checkpoints before you migrate a virtual machine from a host running one version of Hyper-V to a host running another version of Hyper-V. If checkpoints are present, VMM blocks the migration.

  • If a virtual machine contains any checkpoints that have an ISO image file attached, when you migrate the virtual machine, the ISO image files for the checkpoints might be lost.

  • If you attempt to migrate a virtual machine on a Hyper-V host soon after you have removed a checkpoint from the virtual machine, the migration might fail. If you attempt a migration before Hyper-V has finished deleting the checkpoint, the migration will fail and you must repair the virtual machine by using the Undo option of the Repair virtual machine action. For more information about the Undo option, see How to Repair a Virtual Machine ( To avoid this issue, you can ensure that the checkpoint has been deleted or you can wait for Hyper-V to delete the checkpoint for you.

Converting Physical Computers to Hyper-V Virtual Machines

System Center Virtual Machine Manager (VMM) allows you to convert existing physical computers into Hyper-V virtual machines through a process known as physical-to-virtual (P2V) conversion. VMM simplifies P2V conversion by providing a task-based wizard to automate much of the conversion process. Because the P2V process is completely scriptable, you can initiate large-scale P2V conversions through the Windows PowerShell command line.

For more information, see P2V: Converting Physical Computers to Virtual Machines in VMM.

P2V Considerations

VMM P2V is not aware of clusters. Windows Server 2008 failover clustering (and therefore Hyper-V) no longer supports a shared SCSI controller across multiple virtual machines. The only way to build the guest cluster is with iSCSI LUNs for the shared disks of the cluster. If you set up a guest cluster, VMM will treat the cluster as individual virtual machines.

VMM automatically installs Hyper-V Integration Components during the P2V process.

Remote Control of Hyper-V Virtual Machines

Instead of using Virtual Machine Remote Control (VMRC) to control virtual machines on a Hyper-V host by remote control, VMM uses the Remote Desktop Protocol (RDP). Depending on the operating system that is running on the computer that the VMM Administrator Console is installed on, we connect to a different target for RDP and use a different port number. For all supported versions of Windows Server 2008 and for Windows Vista SP1, VMM connects via RDP to the host with the default port of 2179. For any other operating system, VMM connects via RDP to the guest operating system with the default port of 3389.

For information about changing the global default port, see How to Change Remote Connections to Virtual Machines on a Host (

Hyper-V Integration Components

To install the Hyper-V integration components through the VMM Administrator Console, right-click a powered off virtual machine and select Install Virtual Guest Services. The following actions will also automatically install the Hyper-V integration components:

  • P2V conversion

  • V2V conversion

  • Creating a new virtual machine

  • Migrating a virtual machine from Virtual Server to Hyper-V

Virtual Network Considerations

For Hyper-V hosts, VMM 2008 makes use of the virtual networks in Windows Server 2008 virtualization, which are capable of using virtual local area networks (VLANs). A VLAN provides a method for creating independent logical networks within a physical network. This helps ease network administration by separating the logical segments of a LAN that should not exchange data, and this is done by using a LAN that is software-based rather than hardware-based. Because a VLAN configuration is software-based, computers can easily be moved and still maintain their network configurations.

For Hyper-V hosts, VMM uses a port-based approach for tagging VLANs, which means that each port on a virtual network can be configured to be part of different VLANs. You can configure VLANs by assigning a numerical value called a VLAN identifier (VLAN ID) at the port level. Internally, all network traffic originating from that port is tagged with this VLAN ID. Networks, both virtual and physical, that are VLAN-enabled route all tagged network traffic based on the VLAN ID of the tag. This ensures that network traffic for a VLAN is routed only to and from ports on the same VLAN.

For more information, see How to Add or Modify Virtual Networks on a Host (

Storage Considerations

A Hyper-V host supports the following storage options of Windows Server 2008:

  • SCSI and IDE—You must use SCSI if you need to expose more than four virtual disks to your guest. You must use IDE to start from that virtual disk or if there are no Integration Components in the guest operating system. You can use both IDE and SCSI with the same virtual machine.


    For SAN migrations, you must make sure that the LUN is visible on both hosts.

  • iSCSI—You can expose disks directly to the guest operating system by using iSCSI. However, Hyper-V’s virtual BIOS does not support starting from the iSCSI disk directly, so you will still need to have at least one disk available as an IDE disk.

  • Pass-through disks—Hyper-V will let you bypass the host’s file system and access a disk directly. The storage can be either a physical disk internal to the Hyper-V server or a Storage Area Network (SAN) Logical Unit (LUN) mapped to the Hyper-V server. Unlike other storage types, pass-through disks are not limited to 2040 GB.

For more information about the Windows 2008 storage options, see Hardware Considerations.

Hyper-V Hosts

Make sure that new hosts have all updates. If a server is not up to date, it might have a status of Needs Attention. In this situation, right-click the host, choose Properties, and then click the Status tab. If the Virtualization service version status is not Up-to-date, you need to upgrade Hyper-V or apply the BITS QFE.

See Also


How to Enable Shared ISO Images for Hyper-V Virtual Machines in VMM

Other Resources

Hardening Virtual Machine Hosts Managed by VMM