虚拟机里的MariaDB忘记密码了，连接不上，只能重置MariaDB的密码，步骤参考网络
[root@localhost ~]# mysql -uroot -p
Enter password:
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)
[root@localhost ~]# mysql -uroot -p
Enter password:
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)
环境
系统版本
[root@localhost ~]# cat /etc/redhat-release # 查看系统版本
CentOS Linux release 7.4.1708 (Core)
MariaDB版本
Server version: 5.5.56-MariaDB MariaDB Server
重置密码的步骤
1.重启，以安全模式进行MariaDB
[root@localhost ~]# systemctl status mariadb # 查看MariaDB数据库状态
● mariadb.service - MariaDB database server
Loaded: loaded (/usr/lib/systemd/system/mariadb.service; disabled; vendor preset: disabled)
Active: active (running) since Thu 2018-07-12 17:42:01 CST; 4min 37s ago
Process: 1043 ExecStartPost=/usr/libexec/mariadb-wait-ready $MAINPID (code=exited, status=0/SUCCESS)
Process: 989 ExecStartPre=/usr/libexec/mariadb-prepare-db-dir %n (code=exited, status=0/SUCCESS)
Main PID: 1042 (mysqld_safe)
CGroup: /system.slice/mariadb.service
├─1042 /bin/sh /usr/bin/mysqld_safe --basedir=/usr
└─1141 /usr/libexec/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin ...
Jul 12 17:41:56 localhost.localdomain systemd[1]: Starting MariaDB database server...
Jul 12 17:41:57 localhost.localdomain mariadb-prepare-db-dir[989]: Database MariaDB is probably initialized in /...ne.
Jul 12 17:41:57 localhost.localdomain mariadb-prepare-db-dir[989]: If this is not the case, make sure the /var/l...ir.
Jul 12 17:41:58 localhost.localdomain mysqld_safe[1042]: 180712 17:41:58 mysqld_safe Logging to '/var/lib/mysql...rr'.
Jul 12 17:41:58 localhost.localdomain mysqld_safe[1042]: 180712 17:41:58 mysqld_safe Starting mysqld daemon wit...ysql
Jul 12 17:42:01 localhost.localdomain systemd[1]: Started MariaDB database server.
Hint: Some lines were ellipsized, use -l to show in full.
[root@localhost ~]# systemctl stop mariadb # 停止MariaDB数据库
[root@localhost ~]# mysqld_safe --skip-grant-tables # 安全模式进行MariaDB,并且跳过授权表
180706 17:51:16 mysqld_safe Logging to '/var/lib/mysql/localhost.localdomain.err'.
180706 17:51:16 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
2.新建一个ssh连接窗口，进入bash,连接密码库
[root@localhost ~]# mysql -uroot -p # 连接数据库
Enter password: # 不要输入密码，直接回车
Welcome to the MariaDB monitor. Commands end with ; or g.
Your MariaDB connection id is 1
Server version: 5.5.56-MariaDB MariaDB Server
Copyright (c) 2000, 2017, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.
3.重置密码，退出MariaDB数据库
MariaDB [(none)]> use mysql;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
MariaDB [mysql]> update user set password=PASSWORD("admin@1234") where user='root'; # 重置数据库密码
Query OK, 5 rows affected (0.00 sec)
Rows matched: 5 Changed: 5 Warnings: 0
MariaDB [mysql]> flush privileges; # 刷新权限
Query OK, 0 rows affected (0.02 sec)
MariaDB [mysql]> quit
Bye
4.重启MariaDB数据库，使用密码进入MariaDB数据库
[root@localhost ~]# systemctl restart mariadb # 重启MariaDB数据库
[root@localhost ~]# mysql -uroot -p
Enter password:
Welcome to the MariaDB monitor. Commands end with ; or g.
Your MariaDB connection id is 7
Server version: 5.5.56-MariaDB MariaDB Server
Copyright (c) 2000, 2017, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.
MariaDB [(none)]> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| netperformance |
| performance_schema |
| test |
+--------------------+
15 rows in set (0.01 sec)
MariaDB [(none)]> use mysql;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
MariaDB [mysql]> show tables;
+---------------------------+
| Tables_in_mysql |
+---------------------------+
| columns_priv |
| db |
| event |
| func |
| general_log |
| help_category |
| help_keyword |
| help_relation |
| help_topic |
| host |
| ndb_binlog_index |
| plugin |
| proc |
| procs_priv |
| proxies_priv |
| servers |
| slow_log |
| tables_priv |
| time_zone |
| time_zone_leap_second |
| time_zone_name |
| time_zone_transition |
| time_zone_transition_type |
| user |
+---------------------------+
24 rows in set (0.00 sec)
MariaDB [mysql]> select User,Host from user;
+---------+-----------------------+
| User | Host |
+---------+-----------------------+
| root | % |
| root | 127.0.0.1 |
| root | ::1 |
| | localhost |
| root | localhost |
| | localhost.localdomain |
| root | localhost.localdomain |
+---------+-----------------------+
8 rows in set (0.03 sec)
MariaDB [mysql]> exit
Bye
5.查看MariaDB进程是否正常
[root@localhost ~]# ps aux | grep mysql # 查看MariaDB数据库的进程
root 6122 0.0 0.1 113260 1592 pts/0 S+ 17:51 0:00 /bin/sh /usr/bin/mysqld_safe --skip-grant-tables
mysql 6206 0.4 9.2 922568 92556 pts/0 Sl+ 17:51 0:01 /usr/libexec/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --user=mysql --skip-grant-tables --log-error=/var/lib/mysql/localhost.localdomain.err --pid-file=localhost.localdomain.pid
root 6295 0.0 0.0 112660 976 pts/2 R+ 17:55 0:00 grep --color=auto mysql
[root@localhost ~]# ss -tunlp | grep 3306 # 查看MariaDB数据库的端口
tcp LISTEN 0 50 *:3306 *:* users:(("mysqld",pid=1141,fd=14))