I realise I am the cause of my problem.....

I used to use Zabbix monitoring on my 6 system, so when I upgraded to 7, I wanted Zabbix on there also.
The quick and easy install of Zabbix relies on MySQL, so I forced in the community version, and Zabbix works fine.....

Of course, I now realise thats its superceded MariaDB. Including the sandbox version system-mariadb for internal reports.

I can see the scripts to recreate the databases (in the various DEPLOY directories). However, they seem to rely on the core BOOTSTRAP script, which expects system-mariadb to be running.

Whats the best way to get this working - either using MySQL or reverting the whole thing and me getting Zabbix to use Maria?

EDIT: I can see that (most?) of the scripts are set up to run either system-mariadb or system-mysqld but Ive not yet found out how to install system-mysqld ?