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XenSummit has been a tremendous success this year. Thank you to all the speakers for contributing and to all the attendees for making XenSummit an interactive and fun conference with lots of discussions. You can find presentations on slideshare and videos on vimeo. We will also embedded both in the agenda. The slides are also available for download as zip file.

“Windsor”: Domain 0 Disaggregation for XenServer

In a traditional Xen configuration domain 0 is used for a large number of different functions including running the toolstack(s), backends for network and disk I/O, running the QEMU device model instances, driving the physical devices in the system, handling guest console/framebuffer I/O and miscellaneous monitoring and management functions. Having all these functions in one domain produces a complex environment which is susceptible to shared fate on the failure of any one function, has complex interactions between functions (including resource contention) which makes it difficult to predict performance, and has limited flexibility (such as requiring the same kernel for all device drivers).

""Domain 0 disaggregation"" has been discussed for some time as a way to break out domain 0's functions into separate domains. Doing this enables each domain to be tailored to its function such as using a different kernel or operating system to drive different physical devices. Splitting functions into separate domains removes some of the unintentional interactions such as in-domain resource contention and reduces the system impact of the failure of a single function such as a device driver crash.

Although domain 0 disaggregation is not new it is seldom used in practise and much of its use is focussed on providing enhanced security. Citrix XenServer will be moving towards a disaggregated domain 0 in order to provide better security, scalability, performance, reliability, supportability and flexibility. This talk will describe XenServer's “Windsor” architecture and explain how it will provide the above benefits to customers and users. We will present an overview of the architecture and some early experimental measurements showing the benefits.

James Bulpin, Director of Technology, XenServer, Citrix

James is responsible for product architecture and future technology within the XenServer product group at Citrix. After completing his PhD at the University of Cambridge Computer Laboratory James joined XenSource at its beginning in 2005 initially setting up Xen community infrastructure and building automated test systems mostly in support of the Xen 3.0.0 release. He has been involved in every XenServer version since then in various capacities including development, release engineering and automated testing as well as building much of the extensive XenSource lab infrastructure. After a two year spell running the XenServer development group he wanted to get back into a hands-on technical role so took on the job of leading the technical evolution of XenServer to ensure it remains a powerful and flexible platform capable of high performance, scalable and reliable virtualisation.

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