Chapter 6. Uninstalling the para-virtualized drivers

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.

   

   View larger image

   
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.

   

   View larger image

   
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

   Copy to Clipboard Toggle word wrap

   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>
   

   Copy to Clipboard Toggle word wrap

   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>
   

   Copy to Clipboard Toggle word wrap

   Warning

   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.

   Note

   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.