1、停止 MYSQL 服务

bash
[root@iZbp1 ~]# systemctl stop mysqld

2、修改 my.cnf 文件

在最后加上 skip-grant-tables

bash
[root@iZbp1 ~]# vim /etc/my.cnf

# 输入 i 可编辑
# 输入 exit 禁用输入
# 输入 :wq 退出

# 跳过授权表
skip-grant-tables

3、重启 MYSQL 服务

bash
[root@iZbp1 ~]# systemctl restart mysqld

4、进入 MYSQL

bash
# 输入后按两次回车进入
[root@iZbp1 ~]# mysql -uroot -p

mysql> use mysql;
# 将密码制空
mysql> update user set authentication_string='' where user='root';
mysql> exit;

5、注释掉 skip-grant-tables

bash
[root@iZbp1 ~]# vim /etc/my.cnf

# skip-grant-tables

6、重启 MYSQL 服务

bash
[root@iZbp1 ~]# systemctl restart mysqld

# 输入后回车两次即可进行免密登录
[root@iZbp1 ~]# mysql -uroot -p

mysql> use mysql;
mysql> alter user 'root'@'%' identified b '123456';
# 刷新权限、密码重置成功
mysql> flush privileges;

7、异常

MySQL 启动报错：Job for mysqld.service failed because the control process exited with error code. See "systemctl status mysqld.service" and "journalctl -xe" for details.

解决方案： 这是由于/var/lib/mysql目录权限不够导致的

bash
[root@iZbp1 ~]# cd /var/lib/mysql
[root@iZbp1 mysql]# ll

修改权限并启动 mysql
[root@iZbp1 ~]# chown -R mysql:mysql /var/lib/mysql
[root@iZbp1 ~]# chmod -R 777 /var/lib/mysql
[root@iZbp1 ~]# systemctl restart mysqld
[root@iZbp1 ~]# ps -ef |grep mysql
root      2357  2290  0 23:00 pts/2    00:00:00 mysql -uroot -p
mysql     2873     1  0 23:14 ?        00:00:05 /usr/sbin/mysqld
root      3080  3052  0 23:51 pts/3    00:00:00 grep --color=auto mysql

[root@iZbp1 ~]# cd /var/lib/mysql
[root@iZbp1 mysql]# ll
total 192672
-rw-r----- 1 mysql mysql       56 Mar 28 23:10 auto.cnf
-rw-r----- 1 mysql mysql      112 Mar 28 23:14 binlog.index
drwxrwxrwx 2 mysql mysql     4096 Mar 17  2022 blog
-rwxrwxrwx 1 mysql mysql     1676 Nov 26  2021 ca-key.pem
-rwxrwxrwx 1 mysql mysql     1112 Nov 26  2021 ca.pem
-rwxrwxrwx 1 mysql mysql     1112 Nov 26  2021 client-cert.pem
-rwxrwxrwx 1 mysql mysql     1680 Nov 26  2021 client-key.pem
-rwxrwxrwx 1 mysql mysql   196608 Mar 28 23:24 #ib_16384_0.dblwr
-rwxrwxrwx 1 mysql mysql  8585216 Mar  9  2022 #ib_16384_1.dblwr
-rw-r----- 1 mysql mysql     4276 Mar 28 23:14 ib_buffer_pool
-rwxrwxrwx 1 mysql mysql 12582912 Mar 28 23:24 ibdata1
-rwxrwxrwx 1 mysql mysql 50331648 Mar 28 23:24 ib_logfile0
-rwxrwxrwx 1 mysql mysql 50331648 Mar 17  2022 ib_logfile1
-rw-r----- 1 mysql mysql 12582912 Mar 28 23:14 ibtmp1
drwxrwxrwx 2 mysql mysql     4096 Mar 28 23:14 #innodb_temp
drwxrwxrwx 2 mysql mysql     4096 Nov 26  2021 mysql
-rwxrwxrwx 1 mysql mysql 26214400 Mar 28 23:24 mysql.ibd
srwxrwxrwx 1 mysql mysql        0 Mar 28 23:14 mysql.sock
-rw------- 1 mysql mysql        5 Mar 28 23:14 mysql.sock.lock
drwxrwxrwx 2 mysql mysql     4096 Nov 26  2021 performance_schema
-rwxrwxrwx 1 mysql mysql     1676 Nov 26  2021 private_key.pem
-rwxrwxrwx 1 mysql mysql      452 Nov 26  2021 public_key.pem
-rwxrwxrwx 1 mysql mysql     1112 Nov 26  2021 server-cert.pem
-rwxrwxrwx 1 mysql mysql     1676 Nov 26  2021 server-key.pem
drwxrwxrwx 2 mysql mysql     4096 Nov 26  2021 sys
-rwxrwxrwx 1 mysql mysql 16777216 Mar 28 23:24 undo_001
-rwxrwxrwx 1 mysql mysql 16777216 Mar 28 23:24 undo_002