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Red Hat Enterprise Linux 5

Para-virtualized Windows Drivers Guide

Using the para-virtualized drivers Microsoft Windows® Guide

Edition 1.1

Perry Myers

Red Hat Emerging Technologies

Chris Curran

Red Hat Engineering Content Services

Copyright © 2008, 2009 Red Hat, Incorporated.

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Abstract
This guide covers installation and usage of the para-virtualized drivers for fully virtualized Xen-based Microsoft Windows guests on hosts running Red Hat Enterprise Linux 5.2 and later. The para-virtualized drivers provide fully virtualized Microsoft Windows guests with greater throughput and faster latency for storage and networking devices. This guide assumes the reader is familiar with system administration, software installation and configuration of Red Hat Enterprise Linux and Microsoft Windows®environments.
1. Overview
2. Requirements and restrictions
3. Installing and configuring the para-virtualized drivers
3.1. Creating the guest
3.2. Installing the para-virtualized drivers
3.3. Post-installation host configuration
4. Administration tasks
4.1. Hot plugging para-virtualized disks
4.2. Adding para-virtualized network devices
5. Upgrading the para-virtualized drivers
6. Uninstalling the para-virtualized drivers
A. Using virsh to mount a CD-ROM image on an inactive domain
B. Revision History

Chapter 1. Overview

Red Hat Enterprise Linux contains virtualization packages and tools which provide system administrators with the means to run fully virtualized, unmodified, operating system guests on Red Hat Enterprise Linux. This provides companies with the ability to consolidate older systems onto newer, more efficient hardware. This reduces physical space and operating costs involved with powering and cooling older, less efficient systems. Full virtualization incurs worse I/O performance than a native, also known as bare-metal, installations of operating systems.
Para-virtualization is a virtualization technique which involves running modified versions of operating systems. Para-virtualization has input/output (I/O) performance very close to running bare-metal, non-virtualized operating systems. Para-virtualization only works with certain operating systems.
These two techniques, para-virtualization and full virtualization, can be combined to allow unmodified operating systems to receive near native I/O performance by using para-virtualized drivers on fully virtualized operating systems. This guide covers installation and configure the Red Hat Enterprise Linux para-virtualized drivers package for fully virtualized Microsoft Windows® guests.
The para-virtualized drivers package contains storage and network device drivers for fully virtualized Microsoft Windows® guests. The drivers provide Microsoft Windows® guests running on Red Hat Enterprise Linux with enhanced disk and network I/O performance.
This guide requires Red Hat Enterprise Linux 5.2 or later for the virtualization host system. Several versions of Microsoft Windows® are supported as fully virtualized guests. For a complete list of supported guests and other restrictions, refer to Chapter 2, Requirements and restrictions.

Para-virtualized drivers for Red Hat Enterprise Linux guests

Para-virtualized drivers for fully virtualized Red Hat Enterprise Linux guests are also available. Refer to Para-virtualized Drivers Guide or redhat.com/docs for the Red Hat Enterprise Linux Para-virtualized Drivers Guide.

KVM

This guide is about the Xen para-virtualized drivers for Windows.
There are also para-virtualized drivers for KVM-based Windows guests available. The KVM para-virtualized drivers, the virtio drivers, are covered by the Red Hat Enterprise Linux Virtualization Guide.

Chapter 2. Requirements and restrictions

This chapter covers the hardware and software requirements for the para-virtualized Windows drivers.
The para-virtualized Windows drivers can be deployed on x86 (32 bit) and AMD64 or Intel 64 (64 bit) systems running Red Hat Enterprise Linux 5.2 or later. The Itanium platform is presently unsupported for the para-virtualized drivers.
Hosts running AMD64 or Intel 64 (64 bit) Red Hat Enterprise Linux can run 64 bit or 32 bit fully virtualized Windows guests. Mixing 32 bit and 64 bit guest operating systems is supported.
Hosts running x86 (32 bit) Red Hat Enterprise Linux can only run 32 bit guest operating systems.
You require all of the items in this list for the para-virtualized Windows drivers:
  • one or more of the para-virtualized Windows drivers packages. The package installation process is described in Section 3.2, “Installing the para-virtualized drivers”. You only require the packages for the guest architectures you run.
    • xenpv-win-32bit – The driver package for 32 bit Windows versions.
    • xenpv-win-32bit-debug – The debugging driver package for 32 bit Windows versions.
    • xenpv-win-64bit – The driver package for 64 bit Windows versions.
    • xenpv-win-64bit-debug – The debugging driver for 64 bit Windows versions.
  • a system running Red Hat Enterprise Linux 5.2, or later, for the host.
  • at least 10MB of free space on each Windows guest.
  • administrator level access to the Windows virtual machine.
  • root or sudo access to the Red Hat Enterprise Linux host.
Supported operating systems
This section covers the supported Windows virtualized guest operating systems.
Support for para-virtualized drivers is available to virtualized guests running the following Microsoft Windows operating system versions.
  • Windows Server 2003 Service Pack 2 – 32 bit
  • Windows Server 2003 Service Pack 2 – 64 bit
  • Windows Server 2003 R2 Service Pack 2 – 32 bit
  • Windows Server 2003 R2 Service Pack 2 – 64 bit
  • Windows XP – Service Pack 2 – 32 bit
  • Windows XP – Service Pack 3 – 32 bit
  • Windows XP Professional x64 – Service Pack 1 – 64 bit
  • Windows XP Professional x64 – Service Pack 2 – 64 bit
  • Windows Vista – 32 bit
  • Windows Vista – 64 bit
  • Windows Vista Service Pack 1 – 32 bit
  • Windows Vista Service Pack 1 – 64 bit

Note

All mentions of the term "64 bit" in this document refer to AMD64 and Intel 64 systems. Itanium systems are not supported at present by these drivers.
Other restrictions
Some additional technical restrictions apply to the para-virtualized drivers.
The system drive cannot run the para-virtualized block device drivers.
The system drive, identified by the %SYSTEMDRIVE% environment variable in Windows, is the device which contains boot information and system files for the Windows operating system. This device, usually labeled C: drive, contains the Windows directory and cannot use the para-virtualized drivers. The drivers can use a separate partition, logical volume or other physical block device to store applications and non-Windows data. This limitation is due to the limitations of the qemu package.
An example configuration utilizing the para-virtualized drivers.
  • C: drive which contains Windows system files and uses the default, fully virtualized device drivers.
  • D: drive which contains applications and utilizes the para-virtualized drivers.
The para-virtualized device drivers must be installed after the successful creation and installation of the guest operating system.

Chapter 3. Installing and configuring the para-virtualized drivers

3.1. Creating the guest
3.2. Installing the para-virtualized drivers
3.3. Post-installation host configuration
These sections detail installing and configuring the para-virtualized drivers for Microsoft Windows guests on Red Hat Enterprise Linux.
Note that this guide is about Xen-based virtualized guests. Para-virtualized drivers for KVM-based guests are covered in the Virtualization Guide

An important note

The para-virtualized drivers do not support guest booting from a para-virtualized disk. Booting the guest still requires the an emulated IDE driver. Files contained in the Windows directory cannot use the para-virtualized drivers.

3.1. Creating the guest

Creating new Microsoft Windows virtualized guests is outside the scope of this document. For information on creating guests refer to the Red Hat Enterprise Linux Virtualization Guide for information on installing Microsoft Windows virtualized guests. The Red Hat Enterprise Linux Virtualization Guide can be downloaded from www.redhat.com/docs.

3.2. Installing the para-virtualized drivers

This section details the process for installing the para-virtualized drivers on newly created Microsoft Windows guests using virsh or virt-manager.
You can access the Microsoft Windows para-virtualized drivers installer from your guest using either:
  • hosting the files on a network accessible to the guest, or
  • by creating a virtualized CD-ROM device on the guest of the installation disk .iso file.
This guide describes installation from the para-virtualized installer disk as a virtualized CD-ROM device.
Download the para-virtualized drivers package with yum. The package names in the list below are to assist you with choosing the right package for your guest.
Para-virtualized drivers package names
xenpv-win-32bit
The driver package for the 32 bit versions of Windows.
xenpv-win-32bit-debug
The package for debugging the drivers for the 32 bit versions of Windows.
xenpv-win-64bit
The driver package for the 64 bit versions of Windows.
xenpv-win-64bit-debug
The package for debugging the drivers for the 64 bit versions of Windows.
The debug packages (for example, xenpv-win-64bit-debug) are used for debugging the para-virtualized driver inside of the windows guests. These drivers provide users with more verbose reporting and additional tools for debugging and data logging.
To install the .iso file containing the drivers, use yum on a host with the Virtualization channel in RHN enabled.
For the 32 bit package execute the follow command: 
# yum install xenpv-win-32bit
For the 64 bit package execute the follow command: 
# yum install xenpv-win-64bit
This extracts the packaged files to the /usr/share/xenpv-win directory. The Bash output below shows the contents of a /usr/share/xenpv-win directory with both 32 bit and 64 bit drivers and the debugging packages installed. Note the symbolic links (denoted by the -> symbol) linking to the newest version of the para-virtualized drivers. 
$ ls -al /usr/share/xenpv-win
total 13472
drwxr-xr-x   2 root root    4096 Jul 14 17:29 .
drwxr-xr-x 214 root root    4096 Jul 14 17:29 ..
-rw-r--r--   1 root root 3325952 Jul 11 14:58 xenpv-win-32bit-0.97.1.iso
-rw-r--r--   1 root root 3422208 Jul 11 14:58 xenpv-win-32bit-debug-0.97.1.iso
lrwxrwxrwx   1 root root      32 Jul 14 17:29 xenpv-win-32bit-debug.iso -> xenpv-win-32bit-debug-0.97.1.iso
lrwxrwxrwx   1 root root      26 Jul 14 17:29 xenpv-win-32bit.iso -> xenpv-win-32bit-0.97.1.iso
-rw-r--r--   1 root root 3454976 Jul 11 14:58 xenpv-win-64bit-0.97.1.iso
-rw-r--r--   1 root root 3522560 Jul 11 14:58 xenpv-win-64bit-debug-0.97.1.iso
lrwxrwxrwx   1 root root      32 Jul 14 17:29 xenpv-win-64bit-debug.iso -> xenpv-win-64bit-debug-0.97.1.iso
lrwxrwxrwx   1 root root      26 Jul 14 17:29 xenpv-win-64bit.iso -> xenpv-win-64bit-0.97.1.iso
The .iso files in the /usr/share/xenpv-win directory are mounted as virtual CD-ROM devices for the Windows guests in order to install the drivers.
To create the virtualized CD-ROM device you must choose to use either virt-manager (graphical) or virsh (command line).
Mounting the image with virt-manager
Follow Procedure 3.1, “Using virt-manager to mount a CD-ROM image for a Windows guest” to add a CD-ROM image with virt-manager.
Procedure 3.1. Using virt-manager to mount a CD-ROM image for a Windows guest
  1. Open virt-manager, select your virtualized guest from the list of virtual machines and press the Details button.
  2. Click the Add button in the Details panel.
  3. This opens a wizard for adding the new device. Select Storage device from the drop down menu, then click Forward.
  4. Choose the Simple File option and set the file location of the para-virtualized drivers .iso file. The location of the .iso files is /usr/share/xenpv-win if you used yum to install the para-virtualized driver packages.
    If the drivers are stored physical CD, use the Normal Disk Partition option.
    Set the Device type to IDE cdrom and click Forward to proceed.
  5. The disk has been assigned and is available for the guest once the guest is started. Click Finish to close the wizard or back if you made a mistake.
Mounting the image with virsh
To mount .iso images with virsh guests must be either active (on) or inactive (off) state. For inactive guests refer to Appendix A, Using virsh to mount a CD-ROM image on an inactive domain. For mounting the CD-ROM image on an active guest with virsh, follow Procedure 3.2, “Mounting the driver installation CD-ROM image with virsh on an active guest”.
Procedure 3.2. Mounting the driver installation CD-ROM image with virsh on an active guest
  1. Determine the required parameters, including:
    1. An active domain. In the example the domain is called w2k3_32.
    2. An unallocated block device label. The example in the next step uses hdc, if hdc is already allocated choose the next unallocated letter for example hdd. You can verify which drive labels are in use by reading the configuration file generated with the virsh dumpxml w2k3_32 w2k3_32guest.xml. This command generates a configuration file called w2k3_32guest.xml in the current directory.
    3. The correct driver for your windows guest. In the example the xenpv-win-32bit.iso from the xenpv-win-32bit package.
  2. Use the virsh command with the parameters modified for your guest. 
    # virsh attach-disk w2k3_32/usr/share/xenpv-win/xenpv-win-32bit.isohdc --driver file --type cdrom --mode readonly

Warning

The above procedure only works on active domains. Refer to Appendix A, Using virsh to mount a CD-ROM image on an inactive domain for inactive domains.
Para-virtualized drivers executable file names
Executable file name Description
xenpv-win-32bit.exeThe para-virtualized driver package for 32 bit Microsoft Windows installations. This covers most installations.
xenpv-win-32bit-debug.exeThe para-virtualized driver debugging package for 32 bit Microsoft Windows installations.
xenpv-win-64bit.exeThe para-virtualized driver package for 64 bit Microsoft Windows installations. This covers Windows XP Professional® x64 (Service Pack 1 and Service Pack 2), Windows Vista® 64 bit (release and Service Pack 1), Windows Server® 2003 (64 bit) Service Pack 2 and Windows Server® 2003 R2 (64 bit) Service Pack 2.
xenpv-win-64bit-debug.exeThe para-virtualized driver debugging package for Microsoft Windows 64 bit installations.

Note

All mentions of the term "64 bit" in this document refer to AMD64 and Intel 64 systems. Itanium systems are not supported at this time by these drivers.
Procedure 3.3. Installing the para-virtualized drivers on the Windows® guest
  1. The installer may start automatically if you added the virtualized CD-ROM to an active guest. If this occurs skip this step and continue from step 2.
    Start the installer by double clicking the CD drive (E in the example below).
    If Autorun is disabled, start the installer by double clicking the .exe file on the CD.
  2. Once the file is open, the Welcome screen appears. Select Next to proceed.
  3. You are now prompted to select the type of install you want.
    The Complete option installs the network driver, disk driver and source code.
    The Custom option opens another dialog box from which you can choose individual components to install.
    Once you have made your selection, click Next to continue.
  4. Select Install to complete the installation.
  5. The unsigned driver warning (Network and Disk driver has not been digitally signed) dialog box pops up. Select Continue Anyway to install drivers. This dialog box will appear four times, twice for each driver, rhelscsi and then rhelnet.

    Note

    Future releases of Red Hat Para-virtualized Driver for Microsoft Windows will be digitally signed by Windows Hardware Quality Labs (WHQL). Once certified the warning will not appear.
  6. Select Show the README file to view the release notes for the drivers.
    Click Finish to complete the installation.
  7. Reboot the guest.
The the para-virtualized drivers should now be installed on the Microsoft Windows guest.

3.3. Post-installation host configuration

This section covers the post-installation configuration processes required to utilize the para-virtualized drivers. Para-virtualized drivers must be installed on the guest before commencing this section.
Network devices available to guests automatically use the para-virtualized drivers when the guests are rebooted after installation of the drivers. Adding network devices requires special configuration steps, refer to Section 4.2, “Adding para-virtualized network devices”.
Block devices require additional configuration.
Block device configuration
This section covers the procedure for adding and modifying disk entries to enable the para-virtualized drivers. Each guest requires modification in order to utilize the drivers.
Para-virtualized drivers cannot be used for the disk containing the Windows system files. Only secondary disks can be used with the para-virtualized drivers at this time.

Warning

Only make changes to the configuration files in the /etc/xen directory with the libvirt based tools, virsh and virt-manager. Manually editing configuration files in the /etc/xen directory is not recommended and could render your guests inoperable.
Use virsh dumpxml to export the configuration of the virtual machine. 
# virsh dumpxml virt-machine-name > guest.xml
Update the guest configuration to enable the para-virtualized drivers. Red Hat Enterprise Linux 5.2 automatically enables para-virtualized network drivers. Only the block and disk device drivers must be updated.
The guest.xml file locate the section containing the disk configuration should resemble this example. This example uses a hard disk partition called /dev/hda6. 
<disk type='file' device='disk'>
  <driver name='file'/>
  <source file='/var/lib/xen/images/disk1.img'/>
  <target dev='hda'/>
</disk>
<disk type='file' device='disk'>
  <driver name='file'/>
  <source file='/dev/hda6'/>
  <target dev='hdb'/>
</disk>
In this example, the secondary disk updated to use the para-virtualized driver. Change the driver from “file” to “tap:aio” and change the target device from “hdb” to “xvdb”. 
<disk type='file' device='disk'>
  <driver name='file'/>
  <source file='/var/lib/xen/images/disk1.img'/>
  <target dev='hda'/>
</disk>
<disk type='file' device='disk'>
  <driver name='tap' type='aio'/>
  <source file='/dev/hda6'/>
  <target dev='xvdb'/>
</disk>
Redefine the guest using the updated guest configuration file, guest.xml. 
# virsh define guest.xml
The guest can now be restarted with virt-manager or virsh. To restart a guest named virt-machine-name: 
# virsh reboot virt-machine-name

Chapter 4. Administration tasks

4.1. Hot plugging para-virtualized disks
4.2. Adding para-virtualized network devices
This chapter covers additional administration tasks for guests using the para-virtualized Windows® drivers.

4.1. Hot plugging para-virtualized disks

The para-virtualized drivers allow disk hot plugging for Windows fully virtualized guests. To hot plug para-virtualized disks use the virsh command modifying <domain>, <disk image file> and <device node>: 
# virsh attach-disk --driver tap --subdriver aio <domain> <disk image file> <device node>
Using virsh to attach a new, hot plugged disk, labeled /var/lib/xen/images/wxp32-2.img, with the alias /dev/xvdb to the guest named wxp32: 
# virsh attach-disk --driver tap --subdriver aio wxp32 /var/lib/xen/images/wxp32-2.img /dev/xvdb
To detach a disk dynamically, use virsh with the detach-disk option: 
virsh detach-disk <domain> <device node>
This example detaches a disk, /dev/xvdb, from a guest named wxp32: 
# virsh detach-disk wxp32 /dev/xvdb

4.2. Adding para-virtualized network devices

This section covers installation procedures for adding para-virtualized network devices. A key cause problems when not address is the original fully virtualized Realtek device must be disabled to allow the para-virtualized device to work properly. This devices appears in the Device Manager and Procedure 4.1, “Configuring additional para-virtualized network devices” describes how to remove it.
Procedure 4.1. Configuring additional para-virtualized network devices
  1. Follow the standard driver installation procedure from Chapter 3, Installing and configuring the para-virtualized drivers.
  2. Once the installation is complete and the para-virtualized drivers are activated, open Device Manager on your guest. Notice that there are two network devices: one labeled "rhelnet" and one labeled "Realtek". The Realtek device is the fully virtualized network device created by Xen. The Realtek device for the primary network interface should be marked disabled by the installation, if not disable it now.
  3. Shut down the guest before attaching additional network interface controllers.
  4. Add network interface controllers as required.
  5. Boot the guest and log in.
  6. Complete all "Install new hardware wizard" windows which appear after you have logged in.
  7. Open Device Manager. Two new network interface devices appear. Every new physical device has a "rhelnet" device and a "Realtek" device in Device Manager. Right click on every new Realtek device and select Disable.
  8. Your guest now uses the para-virtualized drivers for all network interface devices.
You must use Procedure 4.1, “Configuring additional para-virtualized network devices” every time you install additional physical network interface devices if you require the para-virtualized drivers for your guests.

Chapter 5. Upgrading the para-virtualized drivers

Future updates for the para-virtualized Windows drivers package will be available as bugs are fixed and new features are developed. Follow the procedures documented in this section to update the drivers to newer versions when they become available.
To update the para-virtualized drivers to the latest supported version you require the Virtualization channel from the Red Hat Network. The list para-virtualized driver packages:
xenpv-win-32bit
The driver package for the 32 bit versions of Windows.
xenpv-win-32bit-debug
The package for debugging the drivers for the 32 bit versions of Windows.
xenpv-win-64bit
The driver package for the 64 bit versions of Windows.
xenpv-win-64bit-debug
The package for debugging the drivers for the 64 bit versions of Windows.

Warning

A bug in the drivers causes a Realtek network device to appear for each para-virtualized network device in the guest when the drivers are upgraded or new devices are added. This device can interfere with the para-virtualized network device, including preventing it from functioning.
It is advised to remove these devices before and after upgrading. To avoid this issue, remove the Realtek network devices from the Windows guests before upgrading. For instructions on removing the superfluous devices refer to Procedure 4.1, “Configuring additional para-virtualized network devices”.
Use yum command to install the packaged .iso files to the /usr/share/xenpv-win directory. Modify xenpv-win-32bit with the package name you require from the list. 
# yum update xenpv-win-32bit
Once yum completes, create a virtualized CD-ROM device containing the updated .iso file for the guest.
Follow Procedure 5.1, “Attach the CD-ROM image with virsh” to attach a CD-ROM image with virsh.
Procedure 5.1. Attach the CD-ROM image with virsh
  1. Use the virsh command with the parameters modified for your guest. Refer to Mounting the image with virsh for more information on this step. 
    # virsh attach-disk w2k3_32 /usr/share/xenpv-win/xenpv-win-32bit.iso hdc --driver file --type cdrom --mode readonly
  2. Open My Computer on the guest and open the CD drive (E in the example below). Double click the executable file for your architecture on the CD-ROM drive. The installer may automatically start when the CD-ROM is detected. This starts the installer process which is described in Section 3.2, “Installing the para-virtualized drivers”
After upgrading to the latest driver superfluous Realtek network devices may appear on the guest. These devices are due to a bug in the driver and mused be removed to ensure your guests operate properly. To remove the superfluous devices refer to Procedure 4.1, “Configuring additional para-virtualized network devices”.
Alternate procedure: upgrade with virt-manager
You can re-use existing virtualized CD-ROM devices to upgrading the drivers. To re-use a CD-ROM device with virt-manager:
Procedure 5.2. Re-using a CD-ROM device with virt-manager
  1. Select a CD-ROM device from the list that you no longer need and click the Disconnect button.
  2. Click Connect to choose another disk path.
  3. In the pop up window, choose the location of the para-virtualized drivers .iso image and select OK to allow the guest access on the next boot.
A CD-ROM inserted message appears on the guest and the new CD-ROM image is available on the guest. The drivers can now be installed by running the setup on the CD-ROM. Refer to Section 3.2, “Installing the para-virtualized drivers” for information on using the installer.
After upgrading to the latest driver superfluous Realtek network devices may appear on the guest. These devices are due to a bug in the driver and mused be removed to ensure your guests operate properly. To remove the superfluous devices refer to Procedure 4.1, “Configuring additional para-virtualized network devices”.

Chapter 6. Uninstalling the para-virtualized drivers

This section details the process for uninstalling the para-virtualized drivers from your Microsoft Windows guests.
Procedure 6.1. Removing the para-virtualized drivers
  1. Open the Add or Remove Programs in the Control Panel menu.
  2. Select the Red Hat Xen Para-virtualized Drivers program from the list and click the Remove button.
  3. Once the uninstall process finishes you are prompted to reboot the guest. Click No to the prompt. Shut down the guest instead, do not reboot or restart the guest.
  4. After shutting down the guest, use virsh dumpxml to create an XML configuration file for the guest. Change guest-name and guest.xml to match the name of your guest and the file for saving the configuration. 
    # virsh dumpxml guestname > guest.xml
    For every disk entry (refer to Example 6.1, “Para-virtualized disk entry”) in the guest.xml file modify the para-virtualized disk entry to use the generic virtualized drivers(refer to Example 6.2, “Generic disk entry”).
    Example 6.1. Para-virtualized disk entry
    <disk type='file' device='disk'>
  <driver name='tap' type='aio'/>
  <source file='/var/lib/xen/images/disk2.img'/>
  <target dev='xvdb'/>
</disk>

    Example 6.2. Generic disk entry
    <disk type='file' device='disk'>
  <driver name='file'/>
  <source file='/var/lib/xen/images/disk2.img'/>
  <target dev='hdb'/>
</disk>

    Note

    Xen is limited to 4 fully virtualized IDE devices. You cannot presently convert more than 3 para-virtualized disks to fully virtualized disks due to this limitation.
  5. Restart the guest.
  6. The installer automatically enables the para-virtualized disk driver during the install. The uninstall wizard removed the driver but the device node remains in Windows Device Manager after rebooting. The device node appears as a device named "PCI Device".
    This device causes a "Add New Hardware Wizard" to appear. You can safely close the wizard with the Cancel button.
    To permanently disable the para-virtualized disk driver after uninstalling the driver package you must use the provided scripts in the C:\Program Files\RedHat\XenPV directory. The para-virtualized drivers files are in the directory chosen during the installation process.
    • disableRedHatSCSIDriver.bat - this script disables the para-virtualized disk driver
    • enableRedHatSCSIDriver.bat - this script enables the para-virtualized disk driver
    Double click the disableRedHatSCSIDriver.bat file or execute disableRedHatSCSIDriver.bat from an MS-DOS prompt.

    Batch files in Windows Vista

    To run executable batch files in Windows Vista you must right click the file and select Run as Administrator from the menu that appears. Double clicking on the file runs the batch script without the appropriate privileges to run successfully.
    After running the disable script the "PCI Device" in the Device Manager displays a red X icon, indicating that it is disabled.

Reinstalling uninstalled drivers

To re-install the para-virtualized drivers the enableRedHatSCSIDriver.bat script must be executed before the installation program. Ensure that the red X is gone from the device node before attempting to re-install the drivers using the installer package.
Using virt-manger to uninstall devices
virt-manager can be used instead of virsh to remove devices.
To remove devices, use the Remove for the para-virtualized devices. Removed devices can be added again with the Add wizard.
Once a device has been removed re-adding removed devices causes the device to use the the generic drivers. Use the procedure for adding devices to force the devices to use the para-virtualized drivers. Refer to Block device configuration.

Using virsh to mount a CD-ROM image on an inactive domain

This appendix describes a process which allows users to mount CD-ROM images on inactive domains.
Procedure A.1. Mounting CD-ROM images with virsh on inactive domains
  1. Create an XML configuration file for your guest, replacing guestname with your guest domains name and windowsguest.xml: 
    # virsh dumpxml guestname windowsguest.xml
  2. Add the following entry under the devices tag in the XML configuration file (windowsguest.xml in this example). You must change the source file= parameter to the location of the drivers .iso file and adjust the dev= parameter if you already have a hdb entry. 
    <disk type='file' device='cdrom'>
  <driver name='file'/>
  <source file='/usr/share/xenpv-win-32bit/xenpv-win-32bit.iso'/>
  <target dev='hdb'/>
  <readonly/>
</disk>
  3. Recreate the guest with the updated configuration file 
    # virsh define windowsguest.xml
  4. The guest now has a CD-ROM device containing the para-virtualized drivers once rebooted.
  5. Once the Windows guest has booted, open My Computer and you should see the Red Hat Para-virtualized drivers disk. Click on the disk to continue the installation.

Revision History

Revision History
Revision 1.1Thu Apr 16 2009Chris Curran
Minor edits.
Revision 1.1Fri Jan 23 2009Chris Curran
Copy edit.
Fixes bugs: 481253 and 438748
Revision 1.0Thu May 01 2008Chris Curran
First version.