Virtualization food fight at the Red Hat Summit

Planning to attend the Red Hat Summit? Or still thinking about it? In either case, here’s a sneak preview from presenter (and Red Hat engineer) Rik van Riel. His topic? The popular new virtualization application Xen. Trust us, you’re going to want to be there.

Part 1

With the wide adoption of Xen by Linux distributions, several other virtualization projects (and startups) have come out of the woodwork and are trying to get their technologies upstream.

This has created some uncertainty about open source virtualization technologies. I will explain exactly what is going on, what Red Hat is doing to ensure things will stay compatible, and what our users can do to prepare themselves for the future.

My presentation at the Red Hat Summit will start with an overview of the different open source virtualization technologies for Linux, especially the projects that are actively trying to get adopted upstream. This includes Xen, KVM, VMI, and lguest/lhype.

I will give a technical overview of the projects, explaining the features, goals, advantages, and drawbacks of each. This includes explanations of paravirtualization, the methods of full virtualization, hypervisor versus Linux-based virtualization, and containering.

Another factor to take into account is the way the upstream Linux kernel development process works. The Linux kernel community is wary of maintaining several different virtualization code bases, and is likely to want a common code base with small abstraction layers for the different virtualization technologies. The code has to be high performance as well as easy to maintain, and its developers must play well with the rest of the community. The code has to be compatible with existing virtualization technology or–at the very least–such compatibility should be easy to add.

Some of this code base already exists in the form of the paravirt_ops framework, most of which is already in the upstream kernel today.

And while I’m not usually one for prophecy, I think we know enough about which direction Linux virtualization technology will go. I will present some informed guesses about what the code might look like. Call it predicting the virtualization weather. And make sure to write down the details, so you can poke fun at me at the 2008 Red Hat Summit.

Part 2

The second part of my presentation will highlight what Red Hat is doing to make sure that future versions of Red Hat® Enterprise Linux® will continue to run virtual machines with current versions of RHEL efficiently,and how your system management and deployment tools for Enterprise Linux 5 remain useful with future versions.

Obviously Red Hat needs to ensure that our customers can deploy Enterprise Linux 5 with Xen today, and stay compatible with the virtualization
technology that ends up in the upstream kernel in the future. In order to make that happen, a number of Red Hat’s engineers are involved with the development of Xen, paravirt_ops, and various other upstream virtualization technologies.

One key technology is libvirt, a virtualization management abstraction library that is included in Enterprise Linux 5. Libvirt aims to provide a long-term stable C API for managing virtual machines, with API bindings for Python, Perl, and shell scripts. Currently, libvirt supports various versions of Xen, as well as KVM and QEmu.

Users building their system management tools on top of libvirt will be able to upgrade to future virtualization technologies without having to change their code, since libvirt will take care of changes in technology.

Daniel Veillard, the lead engineer on the libvirt project, will also be at the 2007 Red Hat Summit, explaining how Red Hat has integrated virtualization in Red Hat Enterprise Linux and the Fedora™ Project and how to use the virtualization management tools like libvirt, virt-manager, and cobbler.

More information

• More articles on this topic are available at virt.kernelnewbies.org.
• More Information on libvirt can be found at: libvirt.org
• The 2007 Red Hat Summit will be held in San Diego, CA. Get more information at www.redhat.com/summit.