[root@linux-node1 /var/log/mariadb]# systemctl status mariadb.service
● mariadb.service - MariaDB database server
Loaded: loaded (/usr/lib/systemd/system/mariadb.service; disabled; vendor preset: disabled)
Active: failed (Result: exit-code) since Mon 2019-11-04 01:33:15 EST; 18s ago
Process: 109775 ExecStartPost=/usr/libexec/mariadb-wait-ready $MAINPID (code=exited, status=1/FAILURE)
Process: 109774 ExecStart=/usr/bin/mysqld_safe --basedir=/usr (code=exited, status=0/SUCCESS)
Process: 109740 ExecStartPre=/usr/libexec/mariadb-prepare-db-dir %n (code=exited, status=0/SUCCESS)
Main PID: 109774 (code=exited, status=0/SUCCESS)
Nov 04 01:33:09 linux-node1.example.com systemd[1]: Starting MariaDB database server...
Nov 04 01:33:09 linux-node1.example.com mariadb-prepare-db-dir[109740]: Database MariaDB is probabl...
Nov 04 01:33:09 linux-node1.example.com mysqld_safe[109774]: 191104 01:33:09 mysqld_safe Logging ...'.
Nov 04 01:33:09 linux-node1.example.com mysqld_safe[109774]: 191104 01:33:09 mysqld_safe Starting...ql
Nov 04 01:33:15 linux-node1.example.com systemd[1]: mariadb.service: control process exited, code...=1
Nov 04 01:33:15 linux-node1.example.com systemd[1]: Failed to start MariaDB database server.
Nov 04 01:33:15 linux-node1.example.com systemd[1]: Unit mariadb.service entered failed state.
Nov 04 01:33:15 linux-node1.example.com systemd[1]: mariadb.service failed.
Hint: Some lines were ellipsized, use -l to show in full.
解決方法：
由於之前配置過主從模式
刪除掉主從的配置文件，重新起來了
不能刪除 my.cnf.d文件夾，這樣也會啟動不起來
[root@linux-node2 /etc/my.cnf.d]# systemctl restart mariadb
[root@linux-node2 /etc/my.cnf.d]#