> But this does not as such seem to be akonadi specific; it could also happen in > a case where a system administrator runs a custom mariadb instance managed as > a different instance than what the mariadb/mysql stop scripts handles.
The difference is that if a sysadmin manually has built some custom thing and runs it, they will know about it and are likely able to fix it. In this case the server is run automatically by the Akonadi package. Thus the Akonadi package should do something about the server stop/starts automatically. Surely the Akonadi package has some facility that starts/stops the server? What is that facility? Can we call it from the MariaDB server preinstall script to shut it down, and from the postinstall script to start up again?