no Xen-enabled kernel available in intrepid

[Peter Valdemar Mørch]

There seems to be no kernel available for intrepid that supports Xen.

Here is a forum thread with a summary so far:
http://ubuntuforums.org/showthread.php?p=6230438

[Johnathon (kirrus)]

Thank you for your suggestion. However, the changes you are requesting aren't really a bug and require more discussion, which should be done on an appropriate mailing list or forum. http://www.ubuntu.com/support/community/mailinglists might be a good start for determining which mailing list to use.

[stevegt (stevegt)]

I beg to differ. As far as I can tell from here and from Google,
there is a bug in the decision-making process and/or public statements
surrounding Ubuntu's support of Xen.

I run a mid-sized Xen infrastructure of mixed Debian and Ubuntu
machines. Until intrepid came out, I was deprecating the Debian nodes
in favor of Ubuntu. That's all ground to a halt now. I'm still
waiting for linux-image-*-xen packages to be available in the 8.10
universe. Xen support in Ubuntu appears to be being deprecated;
articles are now scattered all over the net about Ubuntu's support for
KVM at the expense of Xen -- I have yet to find any refutation of
that. So far the trajectory of this bug is reinforcing that
impression. It's as if Mark Shuttleworth's interview about KVM
unintentionally shot Ubuntu Xen in the back. Why would anyone want to
maintain the linux-image-*-xen packages if they think that
Shuttleworth himself doesn't like it?

KVM and Xen are orthogonal -- it almost looks like somehow, ever since
Mark's interview, the Ubuntu community has got it in their heads that
data centers can switch back and forth between two completely
different virtualization platforms that meet different needs.
"Supporting KVM" is not a great excuse for not providing support for
Xen. It's like saying "we don't support Apache, because there's a
perfectly good HTTP server included in the python distribution". It
makes no rational sense.

This has got to be causing damage to Ubuntu's user base. In my own
case, I'm considering the prospect of having to go back to Debian,
even though I consider Ubuntu to be a much better distribution
otherwise. Going backwards like that would be, well, outrageous.

Please tell me this is all a misunderstanding, and that the Xen
packages currently missing from the intrepid repository are an
oversight. Please tell me that there are actually plans in the works
for moving xen from universe to main -- that would make a lot of
sense, considering how critical both Ubuntu and Xen are becoming
in data centers.

[Evan Broder (broder)]

You've filing a bug here against the xen-3.3 package, which provides the Xen userspace, not against Ubuntu's decision making policy. That's something that's certainly not tracked in this section of Launchpad.

Meanwhile, to answer your complaint about Intrepid, I can try to give some context. Previously, the Xen dom0 kernel patches had only been released for the 2.6.18 kernel. The Ubuntu kernel team had been manually forward-porting these patches to run on newer kernels. My understanding is that they decided they just don't have the capability or manpower or something to maintain those patches against the mainline kernel going forward. I suspect there's more discussion on the kernel-team mailing list (https://lists.ubuntu.com/mailman/listinfo/kernel-team).

There is currently an effort by one of the Xen developers to get the dom0 patches incorporated into the mainline kernel tree. I've been hearing since 2.6.27 was released that that should happen with "the next release". I'm starting to become skeptical, but remain hopeful nonetheless. Once that happens, I suspect that the Ubuntu kernel team would be more willing to adopt Xen dom0 support. However, even at that point, that wouldn't be a bug against the userspace packages.

It's always possible to run an Intrepid (or later) system with the Hardy Xen-capable kernel. In fact, I suspect that just adding hardy entries to your sources.list file and installing the linux-image-xen package would get you roughly what you want without any side-effects. Or you could just run Hardy, since it'll be supported until 2013 - that's what I'm doing on all of my Xen hosts.

[stevegt (stevegt)]

Thank you Evan! That's clean, concise information and helps clarify why dom0 support is missing and when it might show up again. This needs to get out more; CNET, The Register, and their ilk have played the KVM thing for sensationalism, I think, and a lot of the Ubuntu communty are playing right into their hands. I'll link to here from a few places to try to add some signal to the noise. https://help.ubuntu.com/community/Xen needs fixing, for instance -- I'll see what I can do.

I like the idea of using the Hardy package. It gave me some other ideas, and I started poking around. For example, It might also make sense to use the Intrepid hypervisor and userland to get the Xen 3.3 support, and then go fetch a recent Xen dom0 kernel from debian. Here's one example of that:

http://www.chrisk.de/blog/2008/12/how-to-run-xen-in-ubuntu-intrepid-without-compiling-a-kernel-by-yourself/

[Frank Abel (frankabel)]

why hardy packages "xen-image-xen0-2.6.17-6-generic-xen0" don't exist? "Package not available" is what ones can read from packages.ubuntu.com

[Johnathon (kirrus)]

Frank, this bug isn't open. If you have a problem, please either open an Answer support ticket, or a new bug :-)

The long and short of it, Xen is not being supported in Ubuntu.