rz
[root@mini2 upload]# tar -xvf mysql-5.7.19-1.el6.i686.rpm-bundle.tar   

rpm -ivh mysql-community-common-5.7.19-1.el6.i686.rpm
rpm -ivh mysql-community-libs-5.7.19-1.el6.i686.rpm 
rpm -ivh mysql-community-libs-compat-5.7.19-1.el6.i686.rpm
rpm -ivh mysql-community-client-5.7.19-1.el6.i686.rpm
rpm -ivh mysql-community-server-5.7.19-1.el6.i686.rpm

[root@mini2 upload]# mysqld --initialize --user=mysql  
2017-08-29T05:22:18.750237Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2017-08-29T05:22:18.754943Z 0 [ERROR] --initialize specified but the data directory has files in it. Aborting.
2017-08-29T05:22:18.755064Z 0 [ERROR] Aborting

[root@mini2 upload]# rm -rf /var/lib/mysql/*

mysqld --initialize --user=mysql

[root@mini2 upload]# service mysqld start 

[root@mini2 upload]# grep 'temporary password' /var/log/mysqld.log
2017-08-29T05:00:02.613275Z 1 [Note] A temporary password is generated for root@localhost: tzqjMvkHH3+C
2017-08-29T05:31:51.340338Z 1 [Note] A temporary password is generated for root@localhost: Adgwggdr2

[root@mini2 upload]# mysql -uroot -p

ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';
grant all privileges on *.* to 'root'@'%' identified by '123456' with grant option