Service failure on boot: systemd-tmpfiles-setup.service

I don't reboot often but it seems when I do lately I'm hitting odd issues :-(. This is another one that doesn't appear anywhere unless you have ssh access and check. After rebooting I have this error below. The error I think is because I have no group systemd-journal in my /etc/group file. I have no idea how it was lost. If I look at the date of the group file it was from January. Ownership of the /var/log/journal directory is currently root:mongodb. I did update something that uses mongo in january. I can only guess that the mongodb group with gid 48 must have been the same as systemd-journal, but I think that probably just means the entry was deleted prior to that install and the number got reused. So I don't know how it got deleted. I've never manually editted that file. I'm thinking I should just add a group for systemd-journal with a new number and then chown -r  /var/log/journal to the new number. Any other directories that should get this group? Other suggestions?

steve

# systemctl status systemd-tmpfiles-setup.service
● systemd-tmpfiles-setup.service - Create Volatile Files and Directories
Loaded: loaded (/lib/systemd/system/systemd-tmpfiles-setup.service; static; vendor preset: enable
d)
Active: failed (Result: exit-code) since Mon 2017-02-20 14:34:52 EST; 4min 38s ago
Docs: man:tmpfiles.d(5)
man:systemd-tmpfiles(8)
Process: 7639 ExecStart=/bin/systemd-tmpfiles --create --remove --boot --exclude-prefix=/dev
(code=exited, status=1/FAILURE)
Main PID: 7639 (code=exited, status=1/FAILURE)

Feb 20 14:34:52 warehouse6 systemd[1]: Starting Create Volatile Files and Directories...
Feb 20 14:34:52 warehouse6 systemd-tmpfiles[7639]: [/usr/lib/tmpfiles.d/systemd.conf:24] Unknown group 'systemd-journal'.
Feb 20 14:34:52 warehouse6 systemd-tmpfiles[7639]: [/usr/lib/tmpfiles.d/systemd.conf:25] Unknown group 'systemd-journal'.
Feb 20 14:34:52 warehouse6 systemd-tmpfiles[7639]: [/usr/lib/tmpfiles.d/systemd.conf:31] Unknown group 'systemd-journal'.
Feb 20 14:34:52 warehouse6 systemd-tmpfiles[7639]: [/usr/lib/tmpfiles.d/systemd.conf:32] Unknown group 'systemd-journal'.
Feb 20 14:34:52 warehouse6 systemd-tmpfiles[7639]: [/usr/lib/tmpfiles.d/systemd.conf:33] Unknown group 'systemd-journal'.
Feb 20 14:34:52 warehouse6 systemd[1]: systemd-tmpfiles-setup.service: Main process exited,
code=exited, status=1/FAILURE
Feb 20 14:34:52 warehouse6 systemd[1]: Failed to start Create Volatile Files and Directories
.
Feb 20 14:34:52 warehouse6 systemd[1]: systemd-tmpfiles-setup.service: Unit entered failed s
tate.
Feb 20 14:34:52 warehouse6 systemd[1]: systemd-tmpfiles-setup.service: Failed with result 'e
xit-code'.