Understanding and Installing Hyper-V Integration Services

Hyper-V Integration Services are a set of processes that may be installed into supported guest operating systems to improve the performance and usability of that guest operating system running within a Hyper-V virtual machine. In some areas, the Hyper-V Integration Services are analogous to the VMware Tools package used to improve the interaction of guest operating systems with the VMware virtualization infrastructure. This chapter will cover guest operating systems for which Integration Services are available, provide an overview of functions performed by the services and provide details on how to install the services on a supported guest operating system.

An Overview of Hyper-V Integration Services

As previously mentioned, Hyper-V Integration Services provide a number of performance and usability enhancing features for Hyper-V based guest operating systems. These services are as follows:

• Hyper-V Time Synchronization Service - Synchronizes the time between the child and parent partitions. Essentially serves to avoid system time drift between the guest operating system running in a child partition and the Hyper-V parent partition.

• Hyper-V Heartbeat Service - The heartbeat service allows the parent partition to detect when a virtual machine has locked up or ceased to function in some other way. The parent partition sends heartbeat messages to the guest operating system in the child partition. It is then the job of the Heartbeat Service installed on the guest as part of the Integration Services to send a response to each of these messages from the parent partition. When the parent partition fails to receive responses from the child partition, it assumes the the Heartbeat Service, and therefore the guest operating system on which it running has encountered problems, and logs the event accordingly.

• Hyper-V Shutdown Service - Allows the guest operating system to be shut down cleanly using the Hyper-V Management interfaces, thereby avoiding the necessity to log into the guest and manually initiate the shutdown procedure. For example, when an administrator selects the Shutdown action for a virtual machine from with Hyper-V Manager, the parent partition communicates with the Shutdown Service running on the guest operating system to notify it of the request. The Shutdown Service then initiates the guest operating system's shut down process by making standard Windows Management Instrumentation (WMI) calls.

• Hyper-V Key/Value Pair Exchange - Provides the ability for the child and parent partitions to exchange configuration information through pre-defined registry entries. In the case of the parent partition, it is able to view, set and delete registry entries in the child partition's guest operating system. In addition, the parent partition configures a number of registry entries into the guest's registry which provide information about the parent.

Understanding Hyper-V Key/Value Pair Exchange

The Key/value pair exchange entries provided by the Hyper-V Key/Value Pair Exchange component of the Hyper-V Integration Services are stored on the guest operating system in the following registry locations:

• HKEY_LOCAL_MACHINE\Software\Microsoft\Virtual Machine\Auto

• HKEY_LOCAL_MACHINE\Software\Microsoft\Virtual Machine\External

• HKEY_LOCAL_MACHINE\Software\Microsoft\Virtual Machine\Guest\Parameters

Registry entries relating to the configuration of the child partition's guest operating system are located in HKEY_LOCAL_MACHINE\Software\Microsoft\Virtual Machine\Auto and are accessible to the parent partition. The specific registry entries are outlined in the following table:

Registry Key	Description
OSMajorVersion	The guest operating system's major version number.
OSMinorVersion	The guest operating system's minor version number.
OSBuildNumber	The guest operating system's build number.
OSVersion	The guest operating system's version number.
OSPlatformId	The guest operating system's platform ID value.
CSDVersion	The most recent Service Pack applied to the guest operating system (e.g. Service pack 1)
ServicePackMajor	The major version number of the most recent Service Pack applied to the guest operating system (e.g. 1).
ServicePackMinor	The minor version number of the most recent Service Pack applied to the guest operating system (e.g. 0).
SuiteMask	The product suites installed on the guest system.
ProductType	Numerical value indicating the guest operating system product type installed in the child partition.
OSName	The name of the guest operating system installed in the child partition (e.g. Windows Server (R) 2008 Enterprise).
ProcessorArchitecture	Numerical value indicating processor architecture identifier
FullyQualifiedDomainName	The fully qualified DNS name that uniquely identifies the guest operating system's fully qualified domain DNS name.

The following figure illustrates the above registry entries listed with the Registry Editor tool on a Windows Server 2008 Hyper-V guest:

In addition, the parent partition inserts the following information about itself into the HKEY_LOCAL_MACHINE\Software\Microsoft\Virtual Machine\Guest\Parameters of the guest operating system allowing the guest to obtain useful information about the host environment on which it is running:

Registry Key	Description
HostName	The domain name system (DNS) name set in the parent partition operating system. If the system is a cluster node, then this is the DNS name of the cluster virtual server.
PhysicalHostName	The non-fully qualified name set in the parent partition operating system.
PhysicalHostNameFullyQualified	The fully qualified name set in the parent partition operating system.
VirtualMachineName	The name of the virtual machine used by the virtualization stack.

WHAT DOES THE DATA EXCHANGE SERVICE DO????