3.2. Windows paravirtualized drivers

The XenSource paravirtualizated network and SCSI drivers provide high performance I/O services without the overhead of traditional device emulation found in first-generation virtualization products. During the installation of a Windows operating system, Xen will use traditional device emulation to present a standard IDE controller and a standard network card to the Virtual Machine. This allows Windows to complete its installation using built-in drivers, but with reduced performance due to the overhead inherent in emulation of the controller drivers.

After Windows is installed, you install the XenSource high-speed paravirtualized drivers. These are on an ISO available to the virtual CD-ROM drive of the Virtual Machine. These drivers replace the emulated devices and provide high-speed transport between Windows and the XenServer product family software.

Note

While a Windows VM will function without them, performance is significantly hampered unless these drivers are installed. Running Windows VMs without these drivers is not supported. Some features, such as live relocation across physical hosts, will only work with the paravirtual drivers installed and active.

The Windows paravirtualized drivers ISO can be attached to the VM by using the "Install Tools" menu in XenCenter, or by directly inserting the built-in xs-tools.iso ISO image to the VM using the CLI. Once the ISO is attached, double-click on the xensetup.exe installer executable and follow the on-screen prompts.