Why akmod fails on F22 for nvidia (and possible other uses)

[Massi Ergosum]

An interesting bug:

https://bugzilla.redhat.com/show_bug.cgi?id=1187111

M.

2015-07-24 16:17 GMT+02:00 Barry Scott <barry at barrys-emacs.org>:
> I did some investigation as to why akmod will fail to install a
> the nvidia dirver when a new kernel turns up.
>
> The problem is that dnf-makecache.service runs at the same time
> as akmods.service. DNF locks the RPM data base which prevents
> akmods from installing the RPM's it built.
>
> Here is a extract from 346.72-2.1-for-4.0.8-300.fc22.x86_64.failed.log
>
> Running transaction
> RPMDB already locked by 2285
>   The application with PID 2285 is: dnf
>     Memory : 116 M RSS (677 MB VSZ)
>     Started: Sat Jul 18 12:09:56 2015 - 06:20 ago
>     State  : Sleeping
> 2015/07/18 12:16:16 akmods: Could not install newly built RPMs. You can
> find them and the logfile 2015/07/18 12:16:16 akmods:
> 346.72-2.1-for-4.0.8-300.fc22.x86_64.failed.log
> in /var/cache/akmods/nvidia/ Looking in the journal shows dnf-makecache
> running at the time that akmods.service need RPMDB access.
>
> I ended up working around the issue with:
>
>         systemctl disable dnf-makecache.service
>         systemctl disable dnf-makecache.timer
>
> I'm not sure what the right systemd unit change will be to have a
> reliable start up. How do you prevent dnf-makecache from running
> until after akmods.service has run given that started off a timer?
>
> At the next kernel release I'll know if this is successful.
>
> Barry
>