I just got the following entry on my boot up today:
systemd: Failed to start Create Volatile Files and Directories.
After a while of searching using my favorit searchengine, I (as usual ;-)) found the most fitting solution in the bbs.archlinux.org.
The solution is given in the manpage of the tmpfiles.d.
If the administrator wants to disable a configuration file supplied by the vendor, the recommended way is to place a symlink to /dev/null in /etc/tmpfiles.d/ bearing the same filename.
So all you have to do is:
# sudo su # cd /usr/lib/tmpfiles.d # cp journal-nocow.conf journal-nocow.conf.bak # rm journal-nocow.conf.bak # ln -s /dev/null journal-nocow.conf
And thats it. Fingers crossed you system will boot without errors.