遇到疑问

我是用yum install mysql mysql-server安装的
用service mysqld start启动服务时，出现如下错误：

Redirecting to /bin/systemctl start mysqld.service Failed to issue method call: Access denied

用systemctl start mysql.service时，出现如下错误：

Failed to issue method call: Unit mysql.service failed to load: No such file or directory. See system logs and 'systemctl status mysql.service' for details.

直接输入mysql出现如下错误：

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)

解决办法

mysql的拥有者是root,而mysql是用mysql用户身份执行当然写不进去了，是系统权限的问题，输入

chown -R mysql:mysql /var/lib/mysql/

就可以了,安装时没有指明用mysql用户。