卸载自带的mysql：执行：
#rpm -qa | grep -i mysql #（有可能是mariadb）
MySQL-client-5.1.49-1.glibc23
#rpm -e --nodeps MySQL-client-5.1.49-1.glibc23
#whereis mysql
mysql: /usr/lib/mysql /usr/share/mysql
#rm -rf /usr/lib/mysql/
#rm -rf /usr/share/mysql
安装mysql：执行
#rpm -ivh MySQL-shared-5.6.41-1.el7.x86_64.rpm
#rpm -ivh MySQL-shared-compat-5.6.41-1.el7.x86_64.rpm
#rpm -ivh MySQL-server-5.6.41-1.el7.x86_64.rpm
#rpm -ivh MySQL-client-5.6.41-1.el7.x86_64.rpm
配置配置文件
#mysqld --initialize
# systemctl start mysqld.service
修改密码
#cat /var/log/mysqld.log
The random password set for the root user at Tue Dec 2221:17:22 2015 (local time):RUmKBqcY
#mysql -uroot -p RUmKBqcY
#set password=password(‘root’)
#flush privileges;