kernel modules and support policy

Asked by Tetsuo Handa on 2011-02-16

I have questions regarding https://help.ubuntu.com/community/Kernel/Compile .

> While it is a learning experience to compile your own kernel, you will not be
> allowed to file bugs on the custom-built kernel (if you do, they will be
> Rejected without further explanation).

Does this mean that I'm allowed to file bugs even if I used a kernel module
that is not supported by Ubuntu?

If yes, to what level? For example, I'll try to identify which component
("the kernel module I used" or "the kernel package provided by Ubuntu") is
the culprit. But sometimes it may be difficult (or impossible) to identify.

Can I file bugs

  (1) only when it is absolutely clear that "the kernel package" is the culprit?

  (2) when it is likely that "the kernel package" is the culprit?

  (3) even when I couldn't identify which component is the culprit?

> If you have a commercial support contract with Ubuntu/Canonical, this will
> void such support.

I've heard that RHEL's commercial support contract becomes void if I used
a kernel module that is not supported by RHEL, even if "the kernel module I
used" was not the culprit.

How does Ubuntu/Canonical's commercial support help? (For example, non
commercial support accepts only case (1) above whereas commercial support
accepts all cases above.)

Regards.

Question information

Language:
English Edit question
Status:
Answered
For:
Ubuntu linux-meta Edit question
Assignee:
No assignee Edit question
Last query:
2011-02-20
Last reply:
2011-02-27
mycae (mycae) said : #1

>Does this mean that I'm allowed to file bugs even if I used a kernel module
>that is not supported by Ubuntu?

Whilst I cannot speak for canonical, I am only a random end-user -- you could always simply disable the kernel module with rmmod. This would remove the module and leave you with a pristine kernel.

If you are still experiencing bugs, then I can't see how anyone would object -- as long as whatever you installed is only from the repositories. Anything outside the repo cannot be supported.

For commercial support, the rules may be more strict -- No idea.

Thanks mycae.

> you could always simply disable the kernel module with rmmod.
> This would remove the module and leave you with a pristine kernel.

Of course I'll do so if I can do so.

Problems in kernel (e.g. memory leak, memory corruption, crash, panic) are
sometimes difficult to find steps to reproduce. It may take weeks or months to
reproduce. On enterprise systems, it is not acceptable to occupy such a long
period only for reproducing the problem without the kernel module.

> If you are still experiencing bugs, then I can't see how anyone would object
> -- as long as whatever you installed is only from the repositories. Anything
> outside the repo cannot be supported.

My understanding is that

  While it is a learning experience to compile your own kernel, you will not be
  allowed to file bugs on the custom-built kernel (if you do, they will be
  Rejected without further explanation).

means

  you will be allowed to file bugs as long as you are using the pristine kernel
  even if you are using kernel modules that are not included in the pristine
  kernel, though you can not file bugs for problems caused by kernel modules
  that are not included in the pristine kernel.

. If my understanding is wrong, I think the wiki page should say something like

  While it is a learning experience to compile your own kernel, you will not be
  allowed to file bugs on the custom-built kernel (if you do, they will be
  Rejected without further explanation). Also, you will not be allowed to file
  bugs if you used kernel modules that are not included in the pristine kernel,
  even if the culprit is the pristine kernel

.

I agree that support will not be provided for custom-built kernel. I also agree
that support will not be provided for kernel modules that are not included in
the pristine kernel.

My question is that there is undocumented zone between "only pristine kernel"
case and "pristine kernel and other kernel modules" case.
What I want to know is the "pristine kernel and other kernel modules" case.
There will be zones for probability on which the culprit is. I described the
zones as (1) (2) (3) cases.

> For commercial support, the rules may be more strict -- No idea.

Enterprise users pay for getting wider support. If support rules for commercial
support is narrower than non commercial support, the answer to
"How does Ubuntu/Canonical's commercial support help?" is "Nothing".

Regards.

mycae (mycae) said : #3

I agree with your interpretation, and that the current wording has an ambiguity.

Though, I would suggest that disallowing bugs with custom non-relevant modules would be ridiculous (think how many people run proprietary wifi drivers.)

There is nothing stopping you from filing bugs as a normal user -- if no-one thinks there is enough info to solve the problem, or if manpower is short, canonical will simply (and often do) ignore the bug. If you think the module is irrelevant (and you think you know why -- just don't mention it!)

> Enterprise users pay for getting wider support.If support rules for commercial
>support is narrower than non commercial support, the answer to
>"How does Ubuntu/Canonical's commercial support help?" is "Nothing".

If you are a large enough customer, you will probably negotiate your own contract with canonical, or at least send an email to them to get a proper response, which is not going to happen here, as canonical do not monitor this forum actively.

Can you help with this problem?

Provide an answer of your own, or ask Tetsuo Handa for more information if necessary.

To post a message you must log in.