Kernel Linux updating

[Alexandru Juncu]

Though the kernel is the heart of the operating system, it's not the
only thing that makes the things go. Putting in a new kernel, isn't
necessarily the answer to all the problems of a system.
Because the userspace utilities are just as important, and you need to
keep them too up to date. Because some versions of a (core) program
might use things that were supported in a version, but not anymore
(this shouldn't happen in a perfect world, but since we're living in
real life, this could happen).

As a best practice, I find that you should update your system
regularly. Updating from version 1 to 2, then to 3 after a couple of
months, then to 4 when that is release usually goes a lot smoother
than going from 1 to 4. Reinstalling the entire distribution would be
a better option, but not always possible in production.

You could just try each version (starting with the LTS ones) until you
find one that works for you.

On 28 June 2013 12:23, Mylene Josserand <Mylene.Josserand at navocap.com> wrote:
> okay ! Thank you for the explanation, Alexandru.
> I see it more clearly :)
>
> What I really want ? Hum, it is for a production purpose.
> We already use a kernel but it a 2.6.32.59 version.
>
> We have some problems and we thought to update it. I had updated it to a
> 3.8 kernel but, of what you say, I should have updated it to a longterm
> version. Which one should I use ?
> In the links you gave me, I see that the 2.6.32 will become EOL in 2014
> and 2.6.34 and 3.0 in 2013. The 3.2 will become an EOL in 2016. Should I
> update to this one ?
>
> And we encountered some problems (about CAN controller to be precise).
> In the CAN mailist, Luka Rahne has the same problem has ours with the
> 3.0.3 kernel. He tested the 3.0.81 and the problem seems to be gone. So,
> also, I wanted to know if the possibly fix between 3.0.3 and 3.0.81
> would have been spreaded to other kernels ? other long term ? stable ?
>
> Thank you again !
>
>
> Mylène
>
>
>
> Le 28/06/2013 10:51, Alexandru Juncu a écrit :
>> On 28 June 2013 11:37, Mylene Josserand<Mylene.Josserand at navocap.com>  wrote:
>>> Hi everyone,
>>>
>>>
>>> I would like to know how the Linux Kernel are updated.
>>> I know that there is the long term kernels, the last stables and the
>>> mainline.
>>> First, what is the real difference between stable and longterm ?
>>>
>>> I see in the Linux Kernel website that the date of the long term (and
>>> the revision number) is changing so I was thinking that there are some
>>> updates on it, right ?
>>>
>>> For example, when an important bug has been fixed, is it fixed in the
>>> new release kernel only ? Or is it applied on old kernels ? Only the
>>> long term ? All ?
>>>
>>> So if I am using the long term 3.4.49 for example (and the current is
>>> 3.4.51), I can just update the 3.4.49 to get the important bugs fix that
>>> have been fixed in the new release (so 3.9.8 right now ?).
>>>
>>>
>>> And if you have some documentation about it, it would be nice !
>>>
>>>
>>> Thank you in advance !
>>
>> Hello!
>>
>> kernel.org [0] is your friend. There is a page explaining the release types [1].
>>
>> In short, Malnline is the newest but somewhat unstable. It's where
>> everything is tested with new features. It compiles, but it not real
>> world tested.
>> When a version is battle tested and does good without doing bad in the
>> real world, it's called stable.
>>
>> The long term versions are ones that are considered milestones. Those
>> kernels could be used in production for many years because they will
>> be patched with security updates, but nothing major will change in
>> their architecture, so the administrator won't have to worry that if
>> he applies a patch it will break the production server.
>>
>> Hopefully I'm not offending anyone with this comparison, but think
>> about it as the Ubuntu versions, if you are familiar with them. You
>> have a new release every 6 months, that has new features, That's
>> stable. Like 13.04. But once every two years they have a long term
>> support version (like 10.04, 12.04, 14.04) that you can rely on for
>> many years. They will be patched for vulnerabilities (ex. 12.04.1
>> probably has secutiy patches like 12.10, but won't have it's new
>> features).
>>
>> So now it's a matter of what you want? Do you want to use it in
>> production? Maybe you would want a tong term version.  Want to use it
>> for your own use? Probably you want the stable. Want to develop new
>> features? You might go for the mainline.
>>
>> Hope it helps.
>>
>> [0] https://www.kernel.org/
>> [1] https://www.kernel.org/category/releases.html