Virtual Machine Architecture

Virtual Server

The virtual machine sessions running in Microsoft Virtual Server are implemented as a set of COM objects which are accessible through the Virtual Server COM API. The virtual machine sessions are isolated from each other and can be viewed as totally separate hardware environments.

A new virtual machine session is initialized when an IVMVirtualMachine object is created using VMVirtualServer::CreateVirtualMachine. The IVMVirtualMachine object contains a standardized set of emulated hardware, with the exception of any virtual hard disks or networks which must be created separately and then attached to the IVMVirtualMachine object. A virtual machine session is the equivalent of a physical hardware system and must be viewed as a separate computer in regards to issues concerning operating system and application software installation and licensing.

The operating state of a virtual machine session is controlled through the IVMVirtualMachine's Startup, TurnOff, Reset, Save, Pause, and Resume methods. Access to the virtual machine's emulated hardware is through the various property values of the IVMVirtualMachine object, which contain either attribute values of the virtual machine or pointers to other COM objects which implement the various emulated hardware devices such as serial ports, network cards, and so on.

There is no access to a virtual machine's operating system or application software unless the Virtual Machine Additions software module is installed in the virtual machine session. Installing Additions enables most of the methods and properties of the IVMGuestOS object associated with the virtual machine session. IVMGuestOS allows Virtual Server to execute application programs inside the virtual machine session, perform an orderly Shutdown of the virtual machine's operating system, and to generate a steady "tick" or "heartbeat" event which allows Virtual Server to monitor the operating state of the virtual machine.

Related topics

Virtual Machine Emulated Hardware
Virtual Machine State Diagram



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Build date: 10/26/2012

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