Not really an issue but is server administration outside of Moodle.

How, exactly, depends upon where/how hosted (might not be allowed to upgrade in that case) and platform (Windows/Linux/Other?).
However, MariaDB folks do have a doc:
One word of caution: before you attempt upgrade to MariaDB, do a site backup - that's and archive of code + a DB dump + minimally moodledata/filedir.
'SoS', Ken
'SoS', Ken