Problem: After an upgrade some services do not start (ie postfix)
You have upgraded your system recently and now some services are not functional. Even manually restarted by
systemctl restart postfix
does not help. You do not even see helpful messages in the logfiles.
Other services could be affected, too.
On checking packet versions you notice they do not match the UCS version reported.
Example for univention-mail-postfix:
UCS version is 4.2-5:
root@ucs:~# ucr search --brief version/version version/patchlevel
version/patchlevel: 5
version/version: 4.2
The installed package version reported by dpkg is 12.0.0-21A~4.3.0.201808241427:
dpkg -l | grep mail-postfix
ii univention-mail-postfix 12.0.0-21A~4.3.0.201808241427 all UCS - postfix configuration
But according to http://updates.software-univention.de/4.2/maintained/4.2-5/all/ the expected version of the package should be 11.0.2-5A~4.2.0.201808231642.
So your system is half-upgraded.
Solution
Restart the upgrade of your system through the console (not ssh) of the server by
univention-upgrade --ignoreterm
and follow the intructions on the screen to upgrade to the latest version.