What's New in Virtual Machine Manager 2008 R2

Applies To: Virtual Machine Manager 2008 R2

System Center Virtual Machine Manager 2008 (VMM) is a comprehensive management solution for the virtualized data center, enabling increased physical server utilization, centralized management of virtual machine infrastructure, and rapid provisioning of new virtual machines by the administrator, delegated administrator, and authorized end users. VMM 2008 can manage hosts that are running Windows Server 2008 with Hyper-V, Virtual Server 2005 R2, and VMware ESX through VirtualCenter Server.

Recently, Windows Server 2008 released an R2 version that included significant feature improvements to Hyper-V. VMM 2008 R2 leverages these new platform enhancements and extends the feature set of VMM 2008. This topic provides an overview of the new features that are included in VMM 2008 R2.

Windows Server 2008 R2 Hyper-V Host Management

With VMM 2008 R2, you can create and manage virtual machines that are running on Windows Server 2008 R2 Hyper-V hosts. When you add a host that is running Windows Server 2008 R2 and that does not have Hyper-V enabled, VMM 2008 R2 automatically enables the Hyper-V role on the host.

VMM 2008 R2 supports the following new features of Windows Server 2008 R2:

  • Live migration between Windows Server 2008 R2 clustered hosts. With live migration, you can migrate a virtual machine from one node of a Windows Server 2008 R2 failover cluster to another node in the same cluster without any downtime. Because the virtual machine does not experience any downtime, the move is completely transparent to the users who are connected to the virtual machine.

  • Network optimization detection during virtual machine placement. VMM 2008 R2 supports both Virtual Machine Queue (VMQ) and TCP Chimney Offload. These are Windows Server 2008 R2 features that improve network performance for virtual machines.

    Network adapters that support the VMQ feature can create a unique network queue for each virtual network adapter and then connect that queue directly to the virtual machine’s memory. This connection routes packets directly from the hypervisor to the virtual machine, bypassing much of the processing in the virtualization stack.

    Network adapters that support the TCP Chimney Offload feature can offload the processing of network traffic from the networking stack. Both features increase network performance and reduce CPU utilization.

  • Hot addition and removal of virtual hard disks (VHDs). In Windows Server 2008 R2, Hyper-V lets users add and remove VHDs from a virtual machine while it is running.

Enhanced Support for SAN Transfers

VMM 2008 R2 provides the following enhancements:

SAN Migration into and out of Clustered Hosts

VMM 2008 R2 supports the use of SAN transfers to migrate virtual machines and highly available virtual machines into and out of a cluster. When you migrate a virtual machine into a cluster by using a SAN transfer, VMM checks all nodes in the cluster to ensure that each node can see the LUN and automatically creates a cluster disk resource for the LUN. Even though VMM automatically configures the cluster disk resource, it does not validate it. You must use the Validate a Configuration Wizard in Failover Cluster Management to validate the newly created cluster disk resource. To migrate a virtual machine out of a cluster, the virtual machine must be on a dedicated LUN that is not using CSV.

Expanded Support for iSCSI SANs

VMM 2008 supports SAN transfers of virtual machines that use initiator-based iSCSI target connections. This requires one iSCSI target for every LUN. VMM 2008 R2 adds support for LUN masking, which allows for multiple LUNs per iSCSI target and expands VMM support for iSCSI SAN vendors.

Enhanced Support for Shared Storage

VMM 2008 R2 provides the following enhancements:

Clustered Shared Volume (CSV) Support

VMM 2008 R2 supports the Windows Server 2008 R2 clustered shared volume (CSV) feature. CSV enables all hosts on a Windows Server 2008 R2 failover cluster to access at the same time virtual machine files on a single shared logical unit number (LUN). Because all nodes on the cluster can access a single shared LUN, virtual machines have complete transparency about which nodes actually own a LUN. This enables live migration of virtual machines within the cluster because all nodes in the cluster can access any LUN.

Support for Sanbolic Clustered File System

VMM 2008 R2 supports the Sanbolic Clustered File System (CFS), a third-party shared volume solution for quick migration on hosts running Windows Server 2008 with Hyper-V, and live migration on hosts running Windows Server 2008 R2 with Hyper-V.

Support for Veritas Storage Foundation for Windows

VMM 2008 R2 supports Veritas Storage Foundation 5.1 for Windows (SFW), an online storage management solution for creating virtual storage devices from physical disks and arrays. Volumes created as part of a cluster resource group by using SFW are detected by VMM 2008 R2 and can be selected during virtual machine placement or migration. An SFW volume is limited to one virtual machine.

Quick Storage Migration

For a Windows Server 2008 R2 host or a Storage VMotion-capable host, you can migrate a running virtual machine’s files to a different storage location on the same host with minimal or no service outage. If you migrate a virtual machine to a host that is running Windows Server 2008 R2 and you use a network transfer, VMM 2008 R2 now gives you the option to specify separate storage locations for each virtual hard disk (.vhd) file for the virtual machine.

Maintenance Mode for Hosts

In VMM 2008 R2, you can start maintenance mode for a Windows-based host anytime you have to perform maintenance tasks on the host, such as applying updates or replacing a physical component.

When you start maintenance mode on a host in a Windows Server 2008 R2 cluster with highly available virtual machines, you can do one of the following:

  • If the option is available, use live migration to evacuate all virtual machines to other hosts on the same cluster. If the migration fails for any virtual machine on the host, maintenance mode is not started on that host and VMM does not migrate back the virtual machines that have already migrated.

  • Place all virtual machines on the host into a saved state.

When you start maintenance mode on a stand-alone Windows-based host, on a host in a Windows Server 2008 cluster, or on a Windows Server 2008 R2 host that has any non-highly available virtual machines, VMM automatically places all virtual machines into a saved state.


When VMM places virtual machines into a saved state, any users of the virtual machines will experience a loss of service.

When you start maintenance mode on any host, VMM automatically does the following:

  • Blocks virtual machine creation operations on the host.

  • Excludes the host from the host ratings during placement.

  • Displays a host status of In Maintenance Mode in Host view of the VMM Administrator Console.

When you stop maintenance mode on a host, VMM allows virtual machine creation operations on the host, includes the host in the host ratings during placement, and displays a host status of OK in Host view of the VMM Administrator Console. However, VMM does not automatically do a live migration to move highly available virtual machines back onto the host in a Windows Server 2008 R2 cluster, and it does not restart any of the virtual machines on the host.

To start or stop maintenance mode, in Host view of the VMM Administrator Console, right-click a host, and then click the appropriate command.

Support for VMware Port Groups for Virtual Switches

VMM uses the network location and tag specified for the virtual network adapter in the hardware configuration to determine the network availability of a virtual machine on a host. In VMM 2008 R2, if you are deploying the virtual machine to a VMware ESX Server host, you can select from the VMware port groups that are available for virtual switches.

Support for Virtual Machine Permissions Assigned in Hyper-V

In VMM 2008 R2, VMM preserves changes that you make to role definitions or role memberships in the root scope of the Hyper-V authorization store. All changes to any other scope are overwritten every half hour by the VMM user role refresher. This differs from user role processing in VMM 2008. In VMM 2008, VMM determines access to virtual machines, hosts, and resources based only on the rights and permissions associated with VMM user roles. VMM 2008 does not make any changes to Hyper-V role definitions and role memberships. It just ignores the Hyper-V authorization store while the hosts and virtual machines are under its management.

For more information about user roles and scopes, see Role-Based Security in VMM.

Support for Windows PowerShell 2.0

VMM 2008 R2 adds support for Windows PowerShell 2.0 in addition to continuing support for Windows PowerShell 1.0. Windows PowerShell 2.0 has new cmdlets, parameters, and variables, and also provides many new features, including the following:

  • Remote management: You can run commands on one computer or on hundreds of computers by using a single command. You can establish an interactive session with a single computer, or you can establish a session that can receive remote commands from multiple computers.

  • Background jobs: By using Windows PowerShell background jobs, you can run commands asynchronously and "in the background" so that you can continue to work in your session. You can run background jobs on a local or remote computer, and you can store the results locally or remotely.

  • Debugger: You can use the Windows PowerShell debugger to help you debug functions and scripts. You can set and remove breakpoints, step through code, check the values of variables, and display a call-stack trace.

For more information about Windows PowerShell 2.0 features, see What's New in Windows PowerShell (https://go.microsoft.com/fwlink/?LinkId=156131).

For more information about the scripting changes in VMM 2008 R2, see What's New in VMM 2008 R2 Scripting.