Hi Francisco, I found an issue very close to this in MariaDB's Jira: https://jira.mariadb.org/browse/CONC-124
I can't tell you for now if this is the way it is supposed to work, must check this point. The second solution you proposed should be preferred as I saw some problem with symlink and above all, it's a persistent solution as /tmp is emptied at boot. Regards, Faustin