成功方案
mysqld_safe --user=mysql --skip-grant-tables --skip-networking &
[root@localhost ~]# mysql -u root mysql
mysql> update user set authentication_string=PASSWORD('passw0rd') where user='root';
[root@localhost ~]# mysql -u root -p
Enter password:
登陸之後還需之行下面的語句修改密碼，使其符合規則
alter user 'root'@'localhost' IDENTIFIED BY 'Passw0rd@' PASSWORD EXPIRE;
或者這一句
SET PASSWORD = PASSWORD('Passw0rd@');
使mysql的root用戶可以遠程鏈接：
mysql -u root –p
mysql>use mysql;
mysql>update user set host = '%' where user = 'root';
mysql>select host, user from user;
FLUSH PRIVILEGES
失敗方案
創建mysql-init文件，內容如下：
ALTER USER 'root'@'localhost' IDENTIFIED BY 'MyNewPass';
然後執行 sudo mysqld_safe --init-file=mysql-init &
然後刪除mysql－init
