mysql忘记密码时，使用mysqld_safe --skip-grant-tables 无效，报错，如下：

Server socket created on IP: '0.0.0.0'.
170205 19:02:18 [Note] Event Scheduler: Loaded 0 events
170205 19:02:18 [Note] /usr/local/mysql/bin/mysqld: ready for connections.
Version: '5.5.37-log' socket: '/tmp/mysql.sock' port: 3306 MySQL Community Server (GPL)
170205 19:04:01 mysqld_safe A mysqld process already exists
170205 19:04:29 mysqld_safe A mysqld process already exists
170205 19:05:25 mysqld_safe Starting mysqld daemon with databases from /usr/local/mysql/data
170205 19:05:25 [ERROR] Can't find messagefile '/usr/local/mysql/share/errmsg.sys'
170205 19:05:25 [Warning] Can't create test file /usr/local/mysql/data/iZ625fgu4w7Z.lower-test
170205 19:05:25 [Warning] Can't create test file /usr/local/mysql/data/iZ625fgu4w7Z.lower-test
/usr/local/mysql/bin/mysqld: Can't change dir to '/usr/local/mysql/data/' (Errcode: 2)
170205 19:05:25 [ERROR] Aborting

170205 19:05:25 [Note]
170205 19:05:25 mysqld_safe mysqld from pid file /usr/local/mysql/data/iZ625fgu4w7Z.pid ended
170205 19:08:53 mysqld_safe The file /usr/local/mysql/bin/mysqld
does not exist or is not executable. Please cd to the mysql installation
directory and restart this script from there as follows:
./bin/mysqld_safe&

仔细分析错误日志后，提示无法从/usr/local/mysql/data启动数据库，但是我的数据库并没有安装在这个目录下面，感觉是 mysqld_safe里面的文件路径不对，打开后果然是，修改了数据的真实路径后，就可以使用mysqld_safe --skip-grant-tables  重置root密码了。

MySQL修改root密码的多种方法