在ubuntu中重置mysql服务器root密码的方法

首先停止mysql服务：

root@webserver:/home/webmaster# service mysql stop

接着采用忽略密码认证模式重新创建一个mysql服务：

root@webserver:/home/webmaster# mysqld --user=mysql --skip-grant-tables --skip-networking &

成功启动后返回pid及其它启动信息

[1] 3591
root@webserver:/home/webmaster# 121005 2:59:27 [note] plugin 'federated' is disabled.
121005 2:59:27 innodb: the innodb memory heap is disabled
121005 2:59:27 innodb: mutexes and rw_locks use gcc atomic builtins
121005 2:59:27 innodb: compressed tables use zlib 1.2.3.4
121005 2:59:27 innodb: initializing buffer pool, size = 128.0m
121005 2:59:27 innodb: completed initialization of buffer pool
121005 2:59:27 innodb: highest supported file format is barracuda.
121005 2:59:27 innodb: waiting for the background threads to start
121005 2:59:28 innodb: 1.1.8 started; log sequence number 1595685
121005 2:59:28 [note] mysqld: ready for connections.
version: '5.5.24-0ubuntu0.12.04.1' socket: '/var/run/mysqld/mysqld.sock' port: 0 (ubuntu)

连接到mysql系统库：

root@webserver:/home/webmaster# mysql -u root mysql

连接到mysql库后直接修改root帐号的密码为新的密码'mynewpasswd':

type 'help;' or '\h' for help. type '\c' to clear the current input statement.

mysql> update user set password=password('mynewpasswd') where user='root';
query ok, 3 rows affected (0.00 sec)
rows matched: 3 changed: 3 warnings: 0

mysql> flush privileges;
mysql> quit;
bye

中止mysql服务进程(pid 3591见前面启动服务时的屏幕信息)：

root@webserver:/home/webmaster# kill 3591

正常启动 mysql服务，并用新密码登录mysql服务器成功：

root@webserver:/home/webmaster#service mysql start
root@webserver:/home/webmaster#mysql -u root -pmynewpasswd