Re: [gentoo-user] No news on kernel upgrade?

[Michael]

On Tuesday, 9 February 2021 13:25:01 GMT n952162 wrote:
> On 2/9/21 12:57 PM, Michael wrote:
> > On Tuesday, 9 February 2021 10:01:04 GMT n952162 wrote:
> >> On 2/9/21 10:05 AM, Dale wrote:
> >>> n952162 wrote:
> >>>> Are extra administrative steps necessary when --sync brings in a new
> >>>>
> >>>> kernel, as in:
> >>>>         https://wiki.gentoo.org/wiki/Kernel/Upgrade
> >>>>
> >>>> I currently have this situation:
> >>>>
> >>>> $ uname -a
> >>>> Linux host *4.19.72-gentoo* #7 SMP Tue Jun 9 19:51:52 CEST 2020 x86_64
> >>>> GNU/Linux
> >>>>
> >>>> $ eselect kernel list
> >>>>
> >>>> Available kernel symlink targets:
> >>>>     [1]   linux-5.4.72-gentoo
> >>>>     [2]   linux-5.4.80-gentoo-r1
> >>>>     [3]   linux-5.4.92-gentoo
> >>>>
> >>>> If an update requires additional steps, shouldn't that have appeared
> >>>> in the news?
> >>>
> >>> It depends I think.  I say think because there may be a binary kernel
> >>> available which will upgrade itself.  I seem to recall reading about it
> >>> on a mailing list somewhere.  I have no experience with it tho.  That
> >>> said, if you use the old method, you have to upgrade the kernel
> >>> yourself.  There are scripts you can use to help automate it a good bit
> >>> but some of us still do it the manual way.  When you do updates, emerge
> >>> will pull in the new sources but the rest is up to you.  I suspect most
> >>> that do it the old way, copy .config over to the new kernel directory,
> >>> run make oldconfig and answer the questions, compile the new kernel,
> >>> copy it to /boot using the right method which there is a few of and then
> >>> configure your bootloader if needed.  The link you posted explains this
> >>> in more detail, and may be more complete too.
> >>>
> >>> I'm trying to remember what that binary kernel thing is called.  I just
> >>> skimmed the messages so it could be something else or not even in the
> >>> tree yet.
> >>>
> >>> Dale
> >>>
> >>> :-)  :-)
> >>
> >> Ah, maybe I have a theory what's going on ... maybe there's no news that
> >> it's time to upgrade the kernel, because it's not meant that the kernel
> >> necessarily needs to be upgraded ... except that it seems that the
> >> virtualbox-modules package might have a (unfortunate) dependency on
> >> that...
> >
> > I'm not sure I understand completely why there should be a news item from
> > portage whenever new kernel sources are updated and downloaded.  It is up
> > the system administrator to configure and build the new sources if
> > desired.
> gentoo policy is that administrators need to keep their systems
> up-to-date.  The promise is, if they do so, the dependency system will
> be reliable.
>
> The kernel version is apparently an exception to this.  The updating
> mechanism does not require that this track the synchronization of the
> portage tree.  Administrators are free to decide what kernel they want
> to use.  This works - except for virtualbox-modules.
>
> > Each time you upgrade your kernel on the host, external modules will
> > require updating/rebuilding.  The set '@module-rebuild' does that instead
> > of having to re-emerge manually each external module.
>
> Yes, in another context, your tip about this helped me to solve a
> separate problem with vbox.  A quick survey didn't find mention of this
> facility in the handbook.  Perhaps I missed it.

Yes, I just found it in the Handbook here:

https://wiki.gentoo.org/wiki/Handbook:AMD64/Installation/Kernel#Post-install.
2Fupgrade_tasks


and in the wiki here:

https://wiki.gentoo.org/wiki/Kernel/
Upgrade#Reinstalling_external_kernel_modules


> > You seem to be running an old kernel.  VBox and its modules changed
> > recently so these will need to be updated - there may be a conflict with
> > older host kernels and as you report you've come across it.
>
> what is the most efficient way for an administrator to known when a new
> kernel is available and advisable?

I don't know of a generic recommended way to go about this, but I have 'sys-
kernel/gentoo-sources' in my world file, so the latest stable version is 
downloaded once available.  Then I build the kernel when convenient and run 
'@module-rebuild' to update any external module packages.

The problem could arise when some package, in this case VBox, requires a later 
kernel than the one you've been running.  I guess things will break and upon 
investigating the kernel version issue will come up in troubleshooting.

For major breakages of the core system I'd expect the devs would have spotted 
it and highlighted it with a news item.


> > The eselect list you showed does not have a selected kernel source.  What
> > is linked to /usr/src/linux on your system?
> >
> > $ ls -l /usr/src/
>
> It is properly linked considering the configuration:
>
> $ ll /usr/src/linux
> lrwxrwxrwx 1 root root 20 Nov  8  2019 /usr/src/linux ->
> linux-4.19.72-gentoo

Right, this particular kernel version is no longer in the tree.  The two 
versions closest to it are 'gentoo-sources-4.14.217' and 'gentoo-
sources-4.19.160'.  Or you could shoot for the latest stable 5.4.92, which 
works fine here, also on a host which runs VBox.