Changes

In [[An Overview of the Hyper-V Architecture]], the significant of the relationship between the Hyper-V parent partition (in which the host instance of Windows Server 2008 runs) and the child partitions containing the guest operating systems was covered in detail. Given the important of this relationship, it is clear that anything which enhances the level of communication between parent and child partitions will serve to improve the performance and manageability of the Hyper-V environment. This is where the Hyper-V Integration Services come into play.  The goal of this chapter of [[Hyper-V Essentials]] is to provide an overview of the Hyper-V Integration Services, provide a list of guest operating systems for which the services are available and, finally, cover the steps involved in installing the services on a guest operating system. 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 areasrespects, 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 . Finally, details on of how to install the services on a supported guest operating systemsystems will be covered.

As previously mentionedHyper-V Integration Services consists of a package of services which, when installed on a Hyper-V guest operating system, improve the performance and manageability of that system running within a Hyper-V virtualization environment. In many respects, Hyper-V Integration Services are analogous to the VMware Tools package used to improve the interaction of guest operating systems within the VMware based virtualization infrastructures. In this section we will take a look at each of the services provided as part of the overall Integration Services package. The 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: * '''Virtual drivers and Hypervisor-aware Kernel''' - Allows the guest operating system to communicate directly with the parent partition over the VMBus when accessing devices and making I/O requests thereby increasing performance of the guest operating system.  * '''Hyper-V Time Synchronization Service''' - The purpose of this services is to synchronize the system time between Hyper-V child and parent partitions (for a detailed description of child and parent partitions, read the chapter entitled [[An Overview of the Hyper-V Architecture]]). This synchronization is important to avoid potential time drift between the guest operating systems running in a child partitions and the Hyper-V parent partition.

* '''Hyper-V Time Synchronization Heartbeat Service''' - Synchronizes The heartbeat service allows the time between the child and parent partitionspartition to detect when a virtual machine has locked up, crashed or otherwise ceased to function. Essentially serves The parent partition sends heartbeat messages to avoid the guest operating system time drift between at regular intervals. It is then the job of the hyper-V Heartbeat Service installed on the guest operating system running in to send a response to each of these heartbeat messages. When the parent partition fails to receive responses from the child partition it assumes that the child's Heartbeat Service, and therefore the guest operating system on which it is running, has encountered problems. the administrative services on the Hyper-V parent partitionwill subsequently log the event accordingly such that it is brought to the attention of a system administrator for corrective action to be taken.

* '''Hyper-V Heartbeat Shutdown Service''' - The heartbeat service Hyper-V Shutdown 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 to be shut down cleanly using Hyper-V management interfaces (such as the child partition. It is then Hyper-V Manager console and the job of Virtual Machine Manager), thereby avoiding the Heartbeat Service installed on necessity to log into the guest as part of operating console and manually initiate the Integration Services to send shutdown procedure. As a response to each of these messages typical example, when an administrator selects the ''Shutdown'' action for a virtual machine from with Hyper-V Manager, the parent partition. When communicates with the parent partition fails Hyper-V Shutdown Service running on the selected guest operating system to receive responses from the child partition, notify it assumes of the the Heartbeat request. The Shutdown Service, and therefore then initiates the guest operating system on which it running has encountered problems, and logs the event accordingly's shut down process by making standard Windows Management Instrumentation (WMI) calls.

* '''Hyper-V Shutdown ServiceVolume Shadow-Copy Requestor''' - Allows the guest operating system to be shut down cleanly using the The Hyper-V Management interfaces, thereby avoiding the necessity to log into the Volume Shadow-Copy Service provides Volume Shadow Copy integration between Volume Shadow Copy enabled guest operating systems 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 entriesin the guest operating system. 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 serve to provide the guest with information about the parentpartition and host system configuration. Additional information on the Hyper-V Key/Value Pair Exchange service is covered later in this chapter.

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 as outlined in the following table:

<td>HostName</td><td>The domain name system (DNS) name set of the operating system running in the Hyper-V parent partition operating system. If the system is a cluster node, then this is the DNS name of the cluster virtual server.</td>

<td>PhysicalHostName</td><td>The non-fully qualified name set of the operating system running in the Hyper-V parent partition operating system.</td>

<td>PhysicalHostNameFullyQualified</td><td>The fully qualified name set of the operating system running in the Hyper-V parent partition operating system.</td>