Troubleshooting Schema Upgrade Fails
If the schema upgrade fails, the database version check and all the other spacewalk services do not start.
spacewalk-service start for more information and hints how to proceed.
You can also run the version check directly:
systemctl status uyuni-check-database.service
journalctl -u uyuni-check-database.service
These commands print debug information if you do not want to run the more general