Xen Orchestra

  • Xen Orchestra provides a web based UI for the management of XenServer installations without requiring any agent or extra software on your hosts nor VMs. The primary goal of XO is to provide a unified management panel for a complete XenServer infrastructure, regardless of pool size and quantity of pools. For those seeking a web based replacement for XenCenter, Xen Orchestra fully supports VM lifecycle operations such as VM creation, migration or console access directly from a browser. Xen Orchestra extends the capabilities of XenCenter to also provide delegated resource access, delta backup, continuous replication, performance graphs and visualizations. Xen Orchestra supports all versions of XenServer, and can be downloaded from https://xen-orchestra.com


Community Overview

User community

The XenServer community of users is incredibly diverse, and often quite engaged and passionate about XenServer. They range from students seeking to learn cutting edge virtualization techniques available to all Xen Project Hypervisor based solutions to large enterprises, governmental agencies and cloud operators running large scale mission critical applications within XenServer virtual machines. Some have administered XenServer for years, while others are new to the XenServer community. While the details of how they came to be XenServer admins varies, they all value the scalability, performance and ease of administration found in modern XenServer. Whether you post a question on the support forums, on the development mailing list, or comment on Twitter, there is a high probability that one of the community has an environment similar to yours and is willing to provide advice to help you succeed.

Community Projects

XenServer is supported by a number of commercial, open source and community lead projects. These projects range in scale from smaller efforts like Xen Orchestra through to major cloud orchestration solutions such as Apache CloudStack and OpenStack. In all cases, community members within those projects have invested in having XenServer be a significant player within their communities due its capabilities and breadth of install base. In addition communities supporting XenServer, those within the XenServer team are active supporters of both upstream projects like CentOS and the Xen Project, but also lateral communities such as libvirt. If you are an active supporter of XenServer within your community, and would like to highlight that, please do let us know. Additionally, if you are interested in having XenServer represented within your community, we are also interested.

Community Verified Solutions

The XenServer teams maintains a hardware compatibility list which contains all the hardware options both Citrix and the respective vendor are willing to offer support for XenServer on. The HCL is far from exhaustive, and while certification kits are available, often the reason a given piece of hardware isn't on the HCL has more to do with the vendor viewing the effort of supporting XenServer as being too costly. This is an area where your voice truly does make a difference. If you are using a given hardware component, and its not on the HCL do voice this to the vendor. Additionally, you can help your fellow users by submitting the solution as "Community Verified". Community Verified is a community lead effort within Citrix Ready organization to highlight hardware and software which has been verified as operational with Citrix products; including XenServer.       

Developing products for XenServer as a platform for OpenStack or CloudStack

Many developers working with the XenServer APIs are also interested in developing products where XenServer is the platform for other Citrix products such as XenDesktop or is a platform underlying OpenStack or CloudStack. This page details a few resources for those interested in developing products for use in OpenStack or CloudStack environments.


CloudStack Apache license for CloudStack

Vendors can be assured that the Apache license will help them protect their IP. Anything built on or around CloudStack can remain proprietary and doesn’t need to be contributed back to the public space. That’s the main benefit of the Apache license vs GPL, and is usually the #1 concern/confusion vendors have.

How to get architectural advice for CloudStack

Vendors can bring architectural discussions to the mailing list: This email address is being protected from spambots. You need JavaScript enabled to view it. (see here for details).

Development Resources for CloudStack

Most discussions occur on the cloudstack-dev mailing list, from time to time some information is summarised on the blogs at https://blogs.apache.org/cloudstack/


Citrix CloudPlatform is a commercial product, powered by Apache CloudStack, is a unified cloud management platform that combines the best cloud foundation for private enterprise workloads with the Amazon-style scale, elasticity and operational efficiency of cloud workloads.

CloudPlatform Links

What products do CloudPlatform clouds use?

Citrix has recently launched a cloud market place search facility, on this page; where CloudPlatform clouds are starting to list themselves, it is interesting to see how many are offering various ISV products to provide functionality such as backup, e.g.:



Development resources for OpenStack

XenServer already has a strong integration with OpenStack – see https://wiki.openstack.org/wiki/HypervisorSupportMatrix for details on some of the features supported by XenServer and how they compare to, for example, KVM/libvirt.

  • In terms of integration with libvirt, although libvirt professes to be cross-hypervisor it is actually quite KVM specific – ranging from the features that it offers to the way it integrates with tools that XenServer also uses, such as qemu. Many of the concepts XenServer provides for enterprise-level virtualisation, such as management of pools, are entirely absent from libvirt. See https://wiki.openstack.org/wiki/XenAPI#Discussion for the rationale for have a separate driver – most of which continues to apply.
  • An interesting point on this is that new “linux hypervisors” supported by OpenStack are continuing to use alternatives to libvirt – see https://github.com/dotcloud/openstack-docker/blob/master/docs/nova_blueprint.md
  • Primarily XenServer’s OpenStack roadmap will be represented by blueprints in the nova project (see https://blueprints.launchpad.net/nova/+specs?searchtext=xenapi) – although when nearing the end of one of the development cycles for OpenStack the list of blueprints outstanding is very small and does not typically represent what will be completed during the next cycle.

Q4 2013 Project Activities


XenServer project planning is actively engaged in delivering on both the promise of transparent development for XenServer, but also actively working to advance the capabilties within XenServer. The following development activities were worked on or completed during Q4 of 2013. Status updates within this article reflect work completed as of January 2014. Work items which have yet to be completed will roll over to the Q1'2014 work item list.  Items which have been completed and merged into trunk are available in the nightly snapshots.

Core Hypervisor

Move to Xen Project Hypervisor 4.3

XenServer 6.2 currently leverages Xen Project hypervisor 4.1.5. With the upgrade to Xen Project hypervisor 4.3, XenServer will benefit from several security and performance improvements. Of particular note are improvements to CPU efficiency, NUMA architectures and the ability to use QEMU upstream vs. QEMU traditional.

Status: Done and merged into trunk.

Control Domain

Move to CentOS 6.4

Enables XenServer to incorporate the latest versions of userspace components. The primary benefits are;

o Improves product quality for end customers by incorporating all security and defect fixes available in the market

o Reduces complexity and risk by reducing integrations of long patch queues

o Enables future exposure of features available in modern kernels

Status: Done and merged into trunk December 16th, 2013. Fixes merged into trunk on January 8th, 2014.

Move dom0 to 64 bits

XenServer currently uses a 32 bit control domain for historical reasons, including availability of legacy device drivers. This legacy model has adversly impacted XenServer's ability to support modern device drivers which require larger operating memory, as well as having imposed artificial scalability limits on XenServer. Migration of dom0 to use a 64 bit control domain will help alleviate many of these issues.

Status: Investigation completed in Q4 2013 and full implementation now underway in Q1 2014.

Upgrade dom0 to Linux 3.10

XenServer 6.2 currently ships with Linux kernel 2.6.32, and as followers of Linux development know kernel 2.6.37 was the first to natively support Xen Project dom0 activitites. Since then, considerable work has occured to make standard Linux distributions take advantage of Xen in the form of pvops kernels, and the Linux 3.10 kernel was designated as a "long term stable" release making it ideal for use with XenServer.

Status: Merged into trunk with 32 bit fixes applied.


Upstream Support for Windows PV drivers

The Citrix XenServer PV drivers currently rely upon a XenServer environment in that they make use of interfaces only available in XenServer, most problematically in patches to XenServer's very out-of-date version of QEMU. The plan for XenServer is to move towards a very minimally patched Xen and a very minimally patched upstream QEMU.

Status: Work ongoing with issues.

Move to userspace blktap3

The goal of the blktap3 project is to obviate the blktap kernel driver (which is not upstreamable) by enabling direct tapdisk-domU IO request passing. That is, tapdisk would access the inter-domain IO ring directly rather than delegating that function to blkback. blktap3 is also referred to as tapdisk3. By moving to tapdisk3, we also avoid the blktap2 kernel driver which isn't included in the upstream kernel.

Status: Work completed in Q4 2014 with 1 defect remaining. The performance testing and defect fixing is now complete in Q1 2014 and ready for integration into trunk.       




Development Snapshots

The following list represents the most recent nightly builds occuring from trunk.  While these builds represent an installable XenServer environment, they are not intended to be deployed in production and no commercial support is available for them.  Importantly, there is no guarantee that an installation based on one of these builds can be upgraded to a release build.  

The contents of each ISO file are:

Base ISO: This bootable ISO represents the main installation CD for XenServer.  If you are looking to install XenServer, then this is the only ISO you will need.

Binary packages: This ISO represents the driver development kit for XenServer.  If you are looking to perform driver development, then this is the ISO you will need.  Note that drivers developed using this kit may only work when installed against the specific version of the base ISO corresponding to a given binary package.

Xen/Dom0 Kernel Sources: This ISO contains the sources for the Xen, XAPI and XenServer binaries.

Dom0 SRPMs: This ISO contains the sources for the RPMs required to build dom0.

Snapshot list

About XenServer

XenServer is the leading open source virtualization platform, powered by the Xen Project hypervisor and the XAPI toolstack. It is used in the world's largest clouds and enterprises.
Technical support for XenServer is available from Citrix.