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

[Peter Nabbefeld]

Am 22.07.2018 um 14:40 schrieb 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

Seems I tried some wrong search string (using grep), now I found the 
following:
Jul 22 09:41:48 tuchola systemd-modules-load[330]: Failed to lookup 
alias 'crypto_user': Function not implemented


>
>>> 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'.

Nope. Only "[PACMAN] Running 'pacman -U linux-4.17.2-1-x86_64.pkg.tar.xz 
linux-headers-4.17.2-1-x86_64.pkg.tar.xz'".

>> they're not in /var/cache/pacman/pkg
> Are there any other `CacheDir' configured in /etc/pacman.conf ?

No.
>> 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
>
So this won't hurt until I recompile some module. Don't have DKMS 
support, either.