Citrix Systems 6.2.0 Appendix A. Windows VM Release Notes

Appendix A. Windows VM Release Notes

There are many versions and variations of Windows with different levels of support for the features provided by

XenServer. This section lists notes and errata for the known differences.

• When installing Windows VMs, start off with no more than three virtual disks. Once the VM and XenServer

Tools have been installed you can add additional virtual disks. The boot device should always be one of the

initial disks so that the VM can successfully boot without the XenServer Tools.

• Multiple VCPUs are exposed as CPU sockets to Windows guests, and are subject to the licensing limitations

present in the VM. The number of CPUs present in the guest can be confirmed by checking Device Manager.

The number of CPUs actually being used by Windows can be seen in the Task Manager.

• The disk enumeration order in a Windows guest may differ from the order in which they were initially added.

This is because of interaction between the PV drivers and the PnP subsystem in Windows. For example, the

first disk may show up as Disk 1, the next disk hotplugged as Disk 0, a subsequent disk as Disk 2, and

then upwards in the expected fashion.

• There is a bug in the VLC player DirectX backend that causes yellow to be replaced by blue when playing video

if the Windows display properties are set to 24-bit color. VLC using OpenGL as a backend works correctly, and

any other DirectX- or OpenGL-based video player works too. It is not a problem if the guest is set to use 16-

bit color rather than 24.

• The PV Ethernet Adapter reports a speed of 1 Gbps in Windows VMs. This speed is a hardcoded value and is

not relevant in a virtual environment because the virtual NIC is connected to a virtual switch. The data rate is

not limited by the advertised network speed.

Quiesced snapshots taken on Windows Server 2008 guests will not be directly bootable. Attach the snapshot disk

to an existing Windows Server 2008 VM to access files for restoration purposes.

Windows Server 2003 32-bit does not boot successfully if any virtual disks larger than 2TB (terabytes) in size are

attached to the VM. See this article in the Windows Hardware Developer Central website.

No known issues

Microsoft Vista recommends a root disk of size 20GB or higher. The default size when installing this template is

24GB, which is 4GB greater than the minimum. Consider increasing this.

Windows XP does not support disks larger than 2TB (terabytes) in size. See this article in the Windows Hardware

Developer Central website.