When using an initrd created by Dracut, systemd fails to find and start plymouthd: systemd[227]: plymouth-start.service: Failed at step EXEC spawning /usr/sbin/plymouthd: No such file or directory systemd[1]: plymouth-start.service: Control process exited, code=exited status=203 systemd[1]: Failed to start Show Plymouth Boot Screen. systemd[1]: plymouth-start.service: Unit entered failed state. systemd[1]: plymouth-start.service: Failed with result 'exit-code'. This is because in /lib/systemd/system/plymouth-start.service, the expected path to plymouthd is /usr/sbin/plymouthd. However, dracut does not copy anything into /usr/sbin at all. So inside the initrd, there is no /usr/sbin/plymouthd, only /sbin/plymouthd. This goes for all other plymouth services, too, such as plymouth-switch-root.service. So either dracut needs to be set to copy over files into /usr/sbin, or the plymouth unit files need to be adjusted to point to the right place.
I'm putting a depends on bug #461478, because it's closely related. This bug might have been caused by some actions being taken in the course of that bug, so clear policy is needed first.