2019独角兽企业重金招聘Python工程师标准>>> 
service mysql start出错，mysql启动不了，解决mysql: unrecognized service错误的方法如下：
[root@ctohome.com ~]# service mysql start
mysql: unrecognized service
[root@ctohome.com ~]# service mysql restart
mysql: unrecognized service
[root@ctohome.com ~]# rpm -q mysql 查询发现mysql已经正常安装
mysql-5.1.52-jason.1
[root@ctohome.com ~]# /etc/rc.d/init.d/mysqld start 直接启动没问题
Starting mysqld: [ OK ]
[root@ctohome.com ~]# ls /etc/rc.d/init.d/mysqld -l
-rwxr-xr-x 1 root root 5509 Dec 18 02:31 /etc/rc.d/init.d/mysqld
[root@ctohome.com ~]# chkconfig mysqld on 设置mysql开机启动
[root@ctohome.com ~]# chmod 755 /etc/rc.d/init.d/mysqld 修改mysqld执行权限
[root@ctohome.com ~]# service mysqld start 搞定
Starting mysqld: [ OK ]
[root@ctohome.com ~]# service mysqld start
Starting mysqld: [ OK ]
[root@ctohome.com ~]# service mysqld status
mysqld (pid 9487) is running...以上转自：http://www.ctohome.com/FuWuQi/aa/511.html
如果以上方法不行的话，还可以参考这个：
连接Mysql提示Can’t connect to local MySQL server through socket的解决方法
http://www.aiezu.com/db/mysql_cant_connect_through_socket.html
主要是修该了：my.cnf文件[mysql socket文件的位置是在/etc/my.cnf中设置的]
[mysqld] datadir=/storage/db/mysql socket=/storage/db/mysql/mysql.sock[mysql] socket=/storage/db/mysql/mysql.sock[mysqldump] socket=/storage/db/mysql/mysql.sock[mysqladmin] socket=/storage/db/mysql/mysql.sock我是先修改这个问题，在按照第一个方法最后实现的。
附：修改Mysql默认密码（默认为空）
修改MYSQL默认账户密码
地址：http://sanpi.blog.51cto.com/620445/952589在安装完MySQL数据库后，必须修改数据库的默认账号密码，以保证数据库的安全性，以下为操作步骤：
#mysql
mysql> use mysql;
Database changed
mysql> select user,password,host from user;
+-------+-------------------------------------------+-----------------+
| user | password | host |
+-------+-------------------------------------------+-----------------+
| root | | localhost |
| root | | email-admin |
| root | | 127.0.0.1 |
| root | | ::1 |
| | | localhost |
| | | email-admin |
| root | | % |
查看发现数据库默认root账号和空账号都未设置密码
修改root用户的密码
mysql> update user set password=PASSWORD('yourpassword') where user='root';
Query OK, 5 rows affected (0.00 sec)
Rows matched: 5 Changed: 5 Warnings: 0
删除空账号
mysql> delete from user where user='';
Query OK, 2 rows affected (0.00 sec)
mysql> select user,password,host from user;
+-------+-------------------------------------------+-----------------+
| user | password | host |
+-------+-------------------------------------------+-----------------+
| root | *5A85E100F2A0D4AD5805DD6E3331937747369E5B | localhost |
| root | *5A85E100F2A0D4AD5805DD6E3331937747369E5B | email-admin |
| root | *5A85E100F2A0D4AD5805DD6E3331937747369E5B | 127.0.0.1 |
| root | *5A85E100F2A0D4AD5805DD6E3331937747369E5B | ::1 |
| root | *5A85E100F2A0D4AD5805DD6E3331937747369E5B | % |
最后刷新缓存，确保新的密码立即开始使用
mysql>flush privileges;
Query OK, 0 rows affected (0.01 sec)
