0.安装MySQL前准备
安装MySQL依赖包
systemctl stop postfixsystemctl disable postfixyum remove postfixyum install libaio perl net-tools -y
创建数据文件目录
mkdir -p /opt/mysql/{data,binlog} 1.卸载系统自带的mariadb软件包
检查系统中存在的mariadb-lib：rpm -qa|grep mariadb或者yum list installed | grep mariadb
mariadb-libs-5.5.56-2.el7.x86_64 删除：rpm -e --nodeps mariadb-libs-5.5.56-2.el7.x86_64或者yum remove mariadb-libs.x86_64 2.从MySQL官网下载并解压：mysql-5.7.21-1.el7.x86_64.rpm-bundle.tar，依次安装4个包：
rpm -ivh mysql-community-common-5.7.21-1.el7.x86_64.rpmrpm -ivh mysql-community-libs-5.7.21-1.el7.x86_64.rpmrpm -ivh mysql-community-client-5.7.21-1.el7.x86_64.rpmrpm -ivh mysql-community-server-5.7.21-1.el7.x86_64.rpm
3.初始化数据库
编辑/etc/my.cnf，更改数据文件路径：
[mysqld] datadir=/opt/mysql/data socket=/tmp/mysqld.sock symbolic-links=0log-error=/opt/mysql/mysqld.log pid-file=/opt/mysql/mysqld.pid [client] socket=/tmp/mysqld.sock
修改完成后，进行MySQL初始化：
chown mysql.mysql -R /opt/mysqlchown mysql.mysql -R /etc/my.cnfchmod 750 -R /opt/mysqlmysqld --initialize --user=mysqlsystemctl start mysqld.servicesystemctl enable mysqldsystemctl daemon-reloadsystemctl status mysqld
初始化完成后会在/mysql/mysqld.log生成随机密码，使用：grep 'temporary password' /mysql/mysqld.log查看随机密码
4.用随机密码登录，修改密码，并设置远程访问
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'NewPass8!';mysql> use mysql;mysql> Grant all on *.* to 'root'@'%' identified by 'root用户的密码' with grant option;mysql> flush privileges;mysql> select user,host from user;
5.创建其他管理用户
mysql> create user 'admin'@'%' identified by 'password'; mysql> GRANT ALL PRIVILEGES ON dbname.* to 'admin'@'%';mysql> flush privileges