[arch-general] Kernel modules not loaded after Linux update

[Ralph Corderoy]

> Hi Peter,

> > > I cannot find the error message from the service again, sorry, so
> > > I cannot tell You, it had to do with some security parameter not
> > > set.
> >
> > It might be in journalctl(1)'s output.
>
> Sorry, cannot find that.  :-/

You have no `journalctl' command, or using it doesn't help find the
error message?  `journalctl -S 2018-07-20' would show all messages
starting from that date, for example.
https://wiki.archlinux.org/index.php/Systemd#Journal

> > If your cache no longer has old packages, you can use the online
> > Archive.
> > https://wiki.archlinux.org/index.php/Downgrading_packages#Arch_Linux_Archive
>
> Thank You, Ralph! I now wonder where the linux-headers are cached

It's a cache so they don't have to still exist in there, especially if
you've done something to clean it at some point.  See when you had
dealings with that package with `grep linux-headers
/var/log/pacman.log'.

> they're not in /var/cache/pacman/pkg

Are there any other `CacheDir' configured in /etc/pacman.conf ?

> Are these headers used for compilation of modules only, or do they add
> some more value to the running linux system, too?

Just the former, I think, but could be wrong.
https://wiki.archlinux.org/index.php/Compile_kernel_module
I've never had it installed, but then I haven't built a kernel module on
this system, nor do I have
https://wiki.archlinux.org/index.php/Dynamic_Kernel_Module_Support

-- 
Cheers, Ralph.
https://plus.google.com/+RalphCorderoy