This is a loaded question because I'm already aware of, and am very interested in ksplice. The problem is that since they were bought by Oracle, they have been forced to pull numerous server distributions from the offerings. The answer isn't as simple as it once was.

I noticed a question on Unix.SE that states:

You can build your own ksplice patches to dynamically load into your own kernel

Great! But how?!

I've installed the free ksplice package in the repo on my desktop (not ksplice-uptrack which is non-free) and now want to generate and apply updates. What's the process? Are there any scripts out there to automate the process?

Moreover, if all the machinery required for rebootless upgrades is sitting there in the kernel (and ksplice package), why on earth aren't we taking advantage of it by default?

Quite recently kGraft was announced. It seems to be roughly the same result so if you have an answer that involves it, I'd be just as happy with that. It's currently a few months from being released though.

Note 1: I am happy for a solution beside ksplice but it has to deliver the same thing: rolling updates to the kernel that can be applied without rebooting the server.

Note 2: I'll say it again; the main ksplice "service" does not support Ubuntu Server. It used to but it doesn't any more. When I talk about wanting to use ksplice, I'm talking about the open source tools in the ksplice package. Any answer that talks about ksplice-uptrack is probably not what I'm after as this is the part that integrates directly with aforementioned "service".