Citrix® Xen® virtual machine (VM) monitor for x86 supports execution of multiple guest operating systems with near-native performance and resource isolation. Xen is open source software, released under the terms of the GNU General Public License. Dell works closely with its partners and the open source community to enable Xen virtualization solutions. This page lists some important links and interesting white papers on Xen.

Important Xen Links

Xen Project Page at University of Cambridge:
http://www.cl.cam.ac.uk/research/srg/netos/xen/

Download Open Source Xen Hypervisor:
http://xen.xensource.com/download/

Xen Summit Presentations:
http://xen.xensource.com/xensummit/

Virtualization Home Page at Novell:
http://www.novell.com/linux/virtualization/

Virtualization Home Page at Red Hat:
http://www.redhat.com/rhel/virtualization/

XenServer and Dell Video Demos

Dell Support Page for Xen Documentation
http://support.dell.com/support/edocs/software/Citrix/

Xen White Papers

Virtualization Using XenEnterprise with Dell PowerEdge Servers and Dell OpenManage
This paper outlines the Xen architecture, outlines value additions of XenSource's XenEnterprise 3.2 product, offers steps to install XenEnterprise on Dell™ PowerEdge™ servers, offers steps to create VMs, offers steps to configure storage repositories, and includes how to manage XenEnterprise hosts using the Dell OpenManage™ suite.

A Performance Comparison of Commercial Hypervisors (from XenSource)
This paper studies the enterprise readiness of hypervisor-based virtualization products from VMware and XenSource. Using the award-winning VMware ESX server hypervisor as a de-facto industry benchmark for performance and enterprise readiness, we present comparative results from an assessment of the XenSource XenServer™ virtualization product family using industry standard benchmarks for performance and scalability.

A Performance Comparison of Commercial Hypervisors (from VMware)
This paper provides a quantitative and qualitative comparison of two virtualization hypervisors available for the x86 architecture—VMware ESX Server 3.0.1 and open source Xen 3.0.3—to validate their readiness for enterprise data centers. A series of performance experiments was conducted on the latest shipping versions (at the time of this study in November 2006) for both hypervisors using the Microsoft® Windows® OS as the guest OS. This white paper discusses the results of these experiments. The discussion in this white paper should help both IT decision makers and end users to choose the right virtualization hypervisor for their data centers.

Creating Fault-Tolerant Xen Virtualization at the Network Adapter Layer
By Scott Collier and Brian Gautreau
In development and production environments, fault tolerance at the physical network layer can be critical. Using the Linux® OS bonding driver with standardized networking configurations enables highly available, fault-tolerant physical layers for Xen guest domains.

Live Migration with Xen Virtualization Software
By David Schmidt and Puneet Dhawan
Virtualization is an emerging trend in enterprise data centers. Using virtualization software, system administrators can run multiple operating systems on a single server, therefore exploiting most of the servers' resources. This article outlines an evaluation deployment of a LAMP (Linux, Apache, MySQL and PHP) application stack for a live migration setup on a VM using Xen open source software and can serve as a guide for those enterprises looking to evaluate Xen in their environment.

An Overview of Xen Virtualization
By Tim Abels, Puneet Dhawan, and Balasubramanian Chandrasekaran
Xen virtualization technology—available for the Linux kernel—is designed to consolidate multiple operating systems to run on a single server, normalize hardware accessed by the operating systems, isolate misbehaving applications, and migrate running OS instances from one physical server to another. This article provides an overview of Xen 3.0 architecture and how it is expected to utilize Intel® Virtualization Technology to enhance manageability and optimize resource utilization in Linux environments.

Xen and the Art of Virtualization
This paper describes the architecture of Xen 1.x.

Live Migration of Virtual Machines
This paper describes the process of Live Migration of VMs across physical hosts.

XEN Troubleshooting

Could not connect vkbd

• Symptom

When installing your guest OS on SLES 10 SP 1, you get the following error message:

Error: Failed to start the VM. Details: Error: Device 0 (vkbd) could not be connected. Hotplug scripts not working. Usage: xen start <Domain name>

• Reason

xen-tools-ioemu is not installed

• Solution

install xen-tools-ioemu like this:

yast -i xen-tools-ioemu