Hi Zbyszek, I would expect the machine-id to be written before mount units are processed, so for that to work I would need to mount /var in the initrd, wouldn't I?
Currently I am trying to just write the machine-id to /etc in the initrd. This makes systemd loose the understanding that /etc is empty though, which might have some side-effects that I am not yet anticipating. Isn't systemd started from inside the initrd once the new root has been set up? Maybe I could set $container_uuid and feed the machine-id to systemd that way? I am afraid that this will lead to some other side-effects, because systemd might assume to be running inside a container. Looks like I will have to do some testing over the weekend:-) Maybe I am lucky and /sys/class/dmi/id/product_uuid is set. Best Regards, Tobias On Fri, Mar 13, 2015 at 1:16 AM, Zbigniew Jędrzejewski-Szmek <[email protected]> wrote: > On Tue, Mar 10, 2015 at 10:23:23PM +0100, Tobias Hunger wrote: >> On Tue, Mar 10, 2015 at 9:33 PM, Tobias Hunger <[email protected]> >> wrote: >> >> presets and machined ID are applied by PID 1, before it begins with >> >> starting any units, hence *really* early on. Note though that actually >> >> /etc/machine-id is used as flag for "is /etc empty". If the file >> >> exists it is assumed that /etc is provisioned properly. If it is >> >> missing PID 1 will generate the machiend id and apply presets. >> > >> > An OS installer could put the machine-id into /usr just fine (and so >> > can I) and systemd could just get it from there if available before >> > generating a new one. >> > >> > It would be nice if the machine-id did not change during to a factory >> > reset: It is used in the logs and changing it will basically make >> > historical log data much harder to analyze. IIRC networkd also uses it >> > to generate persistent MAC addresses for containers and such. >> > >> > So far this seems to be the only critical piece of information that >> > can not get restored via tmpfiles.d. >> >> Thinking about this a bit longer: /usr does not seem like a good idea. >> The machine-id is supposed to be unique and usr-images are meant to be >> reused. >> >> Maybe provide a kernel command line option to force the machine-id if >> none is set yet? > I think this could be an option. We currently check > /var/lib/dbus/machine-id, $container_uuid, and /sys/class/dmi/id/product_uuid. > I think that the first should work for your use case, since you keep /var. > But we also check some commandline option, this seems useful for some > use cases. > > Zbyszek _______________________________________________ systemd-devel mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/systemd-devel
