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Work Underway To Return Xen Support To Fedora 13
Julie188 writes "Details on this are admittedly sketchy, but both Red Hat and Xen.org have gone on record promising that some kind of support for the Xen hypervisor is forthcoming for Fedora users. As we know, on Monday, Fedora 13 was released, chock full of features to appeal to business users. One of the ballyhooed improvements to 13 is virtualization — meaning KVM and only KVM — for Red Hat. Xen was dropped from Fedora a few releases ago and it hasn't come back in 13, except that 13 still supports Xen guests. Meanwhile, 'work is underway in Xen.org to add platform support to Fedora 13 post-release,' promises Xen.org's Ian Pratt."
I was responsible for maintaining a Xen environment for about a year and a half and had much the same experience. We compile our own kernels and in this regard Xen was a nightmare. Do I stick with a 2.6.18 kernel which is the latest supported? If we do that we have to make sure to get backported security fixes. Or do we use forward-ported Xen patchsets which weren't all that reliable and were a pain in the ass to apply?
We finally switched to KVM and suddenly life got a lot easier.
(Going slightly off topic here)For a while we used libvirt and the associated tools, then we discovered Ganeti, a project at Google which has made cluster management a breeze. Libvirt has a "network" driver, but really isn't designed to manage redundant virtualization clusters. Ganeti, on the other hand, is designed specifically for managing clusters, and takes care of all the dirty work like setting up and managing LVM and DRBD. You can build out a new virtual machine, complete with an operating system in just one command, or even do it over the HTTP API. You can use Ganeti with KVM or Xen, but until/unless Xen is in mainline I won't be touching it.
Fedora, not RHEL, is really where Xen belongs anyway. It's exactly the sort of mix of neat ideas, dirty hacks, and blatant wheel re-invention that could only have come from academia, and it was only ever made enterprise-grade by throwing heaps of money at it, and even then only for carefully tested configurations. Yes, it's pretty much single-handedly responsible for commoditizing virtualization, but the combination of the design and the lack of cooperation with the kernel community made it a nightmare to support. Xen is responsible for the existence of KVM because it showed such immense promise, and then delivered extreme frustration and pain.
Since Xen decided long ago it was going to be the center of its own universe, it's really in a great position to do cool experimental things that the kernel community would be more cautious about and the enterprise market wouldn't touch with a 10' pole without seeing a strong proof of concept first. That kind of innovation is a stated goal of the Fedora project.
The only technical advantage Xen enjoys right now is a lack of dependency on hardware virtualization features. Since it's impossible to buy a new machine that you can call a server with a straight face that lacks hardware virtualization, this is meaningless in the enterprise world, but Fedora (like other community distros) has a much broader scope, so there's still a real chance there for necessity to give birth to more invention, much like it did in the early days of Xen when x86 hardware virtualization was still a whisper in the halls at Intel and AMD.
Of course, Xensource/Citrix has already driven away most of the community that would have done this kind of pre-product development, so I'm not holding my breath, but it would be nice to see something more to come of all that work (and years of my own life) beyond simply supporting existing users.
There's no failure quite as dissatisfying as a complete and total solution to the wrong problem.