August 2009 Archives

After having installed Windows 2003 Enterprise Server in a Sun xVM (Xen 3.4.2-rc1-pre-xvm)-Environment, performance was slow due to qemu-dm's tremendous task to emulate ATA/IDE disk access and the Realtek 8139 network chipset.

Xen Block and network drivers however for Windows seemed to exist only in commercial binary-only form supplied from some of the Xen vendors. After googling around, I found the Xen Wiki which included an article about GPL PV drivers for Windows:

http://wiki.xensource.com/xenwiki/XenWindowsGplPv

Inside this article there is a link where these drivers can be downloaded in binary form:

http://www.meadowcourt.org/downloads/

For Windows 2003 Server the driver binary Microsoft Installer Archive (msi) is "wnet".
For my 3.4.2-xen-Setp (Sun xVM with OpenSolaris snv_121 as Dom0) I had to use gplpv_fre_wnet_x86_0.10.0.98-dontuse.msi. The other two versions did not work (resulting in a bluescreening windows...). I did not take "dontuse" literally...

Using OpenSolaris (BFU't to snv_121) and xvm-3.4.2-rc1-pre-xvm (cloned from hg.opensolaris.org) I am able to install Windows 2003 Server using VNC. Neat.

The problem remains that the "qm-demu" daemon running on the Dom0 side to emulate ATAPI disks and a RTL8139 network connection is quite resource consuming. Running online update on a Suse Linux HVM DomU results in qm-demu eating up a whole CPU. With Windows, the same.

Imagine you did a clone of a big database filesystem running in another rdbms instance.

Now you want to use that clone as production file system and you don't need the original file system any more. This won't work because the clone DEPENDS on the original filesystem.

To change that, simply use the promote command to reverse the dependency between clone and original.