問題：命令 $ systemctl start mariadb
報錯 ：Job for mariadb.service failed because the control process exited with error code. See "systemctl status mariadb.service" and "journalctl -xe" for details.
命令$ journalctl -xe 找到問題反饋
查看MariaDB日記：
$ cd /var/log/mariadb
$vim mariadb.log
發現報錯：/usr/libexec/mysqld: unknown variable 'default-character-set=utf8'
錯誤定位：mariadb的配置文件 /etc/my.conf
重新修改配置如下：
[mysqld]
character-set-server=utf8
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
# Settings user and group are ignored when systemd is used.
# If you need to run mysqld under a different user or group,
# customize your systemd unit file for mariadb according to the
# instructions in http://fedoraproject.org/wiki/Systemd
[mysqld_safe]
log-error=/var/log/mariadb/mariadb.log
pid-file=/var/run/mariadb/mariadb.pid
#
# include all files from the config directory
#
!includedir /etc/my.cnf.d
再啓動：$ systemctl start mariadb
成功！