[root@localhost opt]#wget https://cdn.mysql.com//Downloads/MySQL-5.7/mysql-5.7.20-1.el6.x86_64.rpm-bundle.tar

[root@localhost opt]# yum search libaio
[root@localhost opt]# yum install libaio

[root@localhost opt]# rpm -qa | grep mysql
[root@localhost opt]# rpm -qa | grep mariadb

[root@localhost opt]# rpm -e mariadb-libs-5.5.44-2.el7.x86_64 --nodeps

[root@localhost opt]# rpm -ivh mysql-community-common-5.7.20-1.el6.x86_64.rpm
[root@localhost opt]# rpm -ivh mysql-community-libs-5.7.20-1.el6.x86_64.rpm
[root@localhost opt]# rpm -ivh mysql-community-client-5.7.20-1.el6.x86_64.rpm
[root@localhost opt]# rpm -ivh mysql-community-server-5.7.19-1.el7.x86_64.rpm

[root@localhost /]# groupadd mysql
[root@localhost /]# useradd -r -g mysql -s /bin/false mysql

[root@localhost /]# mkdir -p /data/mysql
[root@localhost /]# chown mysql.mysql /data/mysql
[root@localhost /]# ll -d /data/mysql/
drwxr-xr-x. 2 mysql mysql 6 9月 17 17:37 /data/mysql/

[mysqld]
init-connect='SET NAMES utf8mb4'
default-storage-engine=INNODB
character-set-server=utf8mb4
datadir=/data/mysql
socket=/var/lib/mysql/mysql.sock
assorted security risks
symbolic-links=0
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
validate_password=off
sql_mode=STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
lower_case_table_names=1
[mysql]
default-character-set = utf8mb4
[client]
default-character-set = utf8mb4

[root@localhost /]# /usr/sbin/mysqld --initialize --user=mysql

[root@localhost /]# grep "root@localhost" /var/log/mysqld.log

mysql> set password = password('123456');

mysql> use mysql; 
mysql> select host,user,password from user; 
mysql> update user set password=password('xxxxxx') where user='root'; 
mysql> update user set host='%' where user='root' and host='localhost'; 
mysql> flush privileges;