一、操作思路：
1）停止mysql服务
2）启动时添加“--skip-grant-tables”参数
3）修改密码
4）重启mysql服务
二、执行过程
# netstat -tunlp | grep 330*
tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 13157/mysqld
tcp 0 0 0.0.0.0:3307 0.0.0.0:* LISTEN 13874/mysqld
tcp 0 0 0.0.0.0:3308 0.0.0.0:* LISTEN 12388/mysqld
# 这里假设忘记的是3308实例的root密码
# 先安全关闭另外两个实例
# /data/3306/mysql stop
# /data/3307/mysql stop
# killall mysqld
# mysqld_safe --defaults-file=/data/3308/my.cnf --skip-grant-tables &
[2] 10883
# 161011 22:05:47 mysqld_safe Logging to ‘/data/3308/mysql_oldboy3308.err‘.
161011 22:05:48 mysqld_safe Starting mysqld daemon with databases from /data/3308/data
# mysql -uroot -p -S /data/3308/mysql.sock
Enter password: （这里直接回车就进去了）
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.5.32-log Source distribution
Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type ‘help;‘ or ‘\h‘ for help. Type ‘\c‘ to clear the current input statement.
mysql> update mysql.user set password=password("redhat123456") where user=‘root‘;
Query OK, 4 rows affected (0.00 sec)
Rows matched: 4 Changed: 4 Warnings: 0
# 更新root账号的密码
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
# 刷新权限
# netstat -tunlp | grep mysql
tcp 0 0 0.0.0.0:3308 0.0.0.0:* LISTEN 11620/mysqld
[1]+ Done mysqld_safe --default-file=/data/3308/my.cnf --skip-grant-tables --user=mysql
# pkill mysql
# netstat -tunlp | grep mysql
# /data/3308/mysql start
Starting MySQL...
# echo $?
0
三、验证
# mysql -uroot -predhat123456 -S /data/3308/mysql.sock Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 1 Server version: 5.5.32-log Source distribution Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type ‘help;‘ or ‘\h‘ for help. Type ‘\c‘ to clear the current input statement. mysql>
时间： 2024-08-04 04:05:38