Why are only some versions of the kernel backported to certain releases?

With regard to kernels and backports, I noted a backported kernel available to 10.04 LTS builds, slightly older than the cutting-edge kernels in 10.10. Any reason for a lack of backports for them? (although the currently backported kernel for lucid is 2.6.35, >= 2.6.36 is newer and seems to be in the 10.10 and later repositories)

Solution 1:

Speaking for the Ubuntu Kernel Team, The plan is to provide backport kernels in lockstep with Stable release updates. The Maverick kernels are unavailable currently due to a toolchain change that is precluding them from building. Once that has been fixed, there will be additional kernels available to LTS from Maverick. Once Natty is officially released there will be a backport kernel available for it as well. That is the plan going forward as it has been explained to me. Once a version is released, a new kernel will be available in backports soon after.

As we discussed offline, these kernels are built expressly for the -server release and are not supported on the desktop even if they work. I'd also like to point out that the reason we provide these kernels (for those reading who want to understand why they would care about backported kernels) is to provide -server users with the most current updates for new supported hardware.

I hope that helps. :-)

Solution 2:

as psusi says Time, I would also like to add that more people in Ubuntu world use the latest release. Some might be still using LTS or ever older, release but I have seen that most people use latest or previous release at max(lesser people than latest)

Most of the focus is on managing kernels in the development release. Once a release is out, providing backports is not a major incentive. It needs commitment and who knows it might break the system too. When working on latest release they have a huge number of people testing it out via Alpha releases, that huge number would not be available for testing backports.

This is probably one more reason why Ubuntu backports project is not very active. The people working on it cite time-constraint and no-real-incentive to do it.

Solution 3:

Time. Someone has to take the time to backport, and it just isn't a very high priority.