Monthly Archives: April 2009

VM Snapshots Code Released

Patrick Colp at the recent Xen Summit at Oracle described his project and has announced the release of the source code. From his email:
I’ve been working on VM snapshots/CoW for Xen (as seen at Xen Summit this year). I’m happy to release my first version.

There are some known issues with capturing page dirties for HVM guests. I think it’s related to the QEMU code (I believe I’m not catching the pages that QEMU dirties). However, it works with both 32-bit and 64-bit PV guests.

This release includes modifications to Linux, Xen, and some tools (a
library, FUSE fs, and testing tool).

The FUSE file system will take a snapshot if you try to create a file in
the directory you mount the xencowfs file system too.

The testing tool pauses a domain, enables CoW, takes a dump of the CoW image, takes two live memory dumps, unpauses the domain for a bit, then takes another CoW image. It compares all the images and reports on which pages are different.

These patches are against xen-unstable revision 19425, however I had no trouble patching them against the current revision of xen-unstable (19553).

Please remember this is an alpha release, so there is likely to be some
problems. Please let me know if you find any! Releases abiCloud

abiCloud is an open source cloud computing platform platform.

It allows to quickly create a private cloud inside an organization’s firewall, and manage it with a rich user interface. Next version will allow to also deploy images in external clouds, creating an hybrid environment.

abiNtense is a developing framework for quickly create distributed applications.

It also offers a multi-architecture middleware for making it really easy.

For more info, go to Booth at NGDC/CloudWorld/OpenSource World

Xen Community:

We have a booth scheduled to promote, the Xen Hypervisor, and associated projects in August at the NGDC/CloudWorld/OpenSourceWorld Conference in San Francisco at the Moscone Center. The event is August 12 – 13, 2009 and I have 5 passes available for people interested in helping to work the booth. I also have 20 passes available for people who want to attend the exhibit hall but are not interested in working at the booth.

Please contact me if you have any interest in working at the booth or coming to the event.  Booth volunteers will not have to work the entire time so you will have an opportunity to look around at the other exhibitors.

Installing and Running HXEN

For those of you who have not tried the new HXEN – Hosted Xen project, I want to go through some of the issues I had installing and running the hypervisor on my Windows XP Tablet machine.


*** Make sure that your machine has Virtualization hardware enabled (E.g. Intel VT-d) ***
*** Make sure that your user profile has administrative rights on the machine you are running ***

1) Download the HXEN application from

2) Download and install OpenVPN-2.0.9 from Only the TAP-Win32 Virtual Ethernet Adapter needs to be installed for this application.

3) Open Networking Window and change the name of the newly appearing Networking Connection to “kxen-tap”. NOTE – I changed the “Local Area Connection-3” icon to kxen-tap.

4) Internet Connection Sharing – I run my Wireless Network Connection as the active Internet source so I opened up the properties of that icon, selected Advanced – and checked “Allow other network users to connect through this computer’s Internet connect” which also forced me to select kxen-tap in the pull down  menu.

5) In the directory where you stored the downloaded HXEN files you will see an images folder and may need to create an isos folder as well. The Startvm.bat file will need to be updated to give the application the proper DISKIMAGE and CDIMAGE.

* If you create a new folder please select properties and unmark the ReadOnly setting
* The Readme has instructions on creating an empty disk image createimg.exe images\testdisk.img 8 1024 1024 1024 for use with a valid CD iso image .
* I obtained a valid ISO image of Vista and placed it in my iso folder

6) Double click StartVM.bat and the application will open a new window where the VM operating system will load.


** I have seen problems stopping the ioemu.exe process from stopping using the Windows Task Manager
** I tried to run a Fedora9 image (.img) file with no Disk Image file (.iso) and the system cannot load that image. Still working on this issue to see if there is a solution
** I am able to bring up Vista on my VM but during installation the OS gives everyones favorite blue screen of death. I am still looking into this issue


*** I used the debugview ( tool for kernal trace.  You need to enable the option to display kernel messages, then send its output to a file for later checking.
*** The HXEN tool creates a stderr and stdout file in the same directory that the .bat file is run from. These tools can give you relevant information on what is happening.

Looking to see comments from others who have tried the inital HXEN release for more feedback.