systemctl start mariadb.service
エラー出る
Job for mariadb.service failed because the control process exited with error code. See "systemctl status mariadb.service" and "journalctl -xe" for details.
/var/log/message を確認
Database MariaDB is not initialized, but the directory /var/lib/mysql is not empty, so initialization cannot be done.
の記述を見つける
/var/lib/mysql/mysql.sock
があるけど、権限を777とかにしてもダメだった
ためしに/var/lib/mysql/mysql.sockを削除したら出来た