找找/usr/share/mysql/my.cnf，没有的话用find命令查找一下：

 sudo find / -name my.cnf

或者查看进程信息查看加载了哪个配置文件

 cat /proc/$(pidof mysqld)/cmdline | tr '\0' '\n'

mysql可以在启动命令上加上 --defaults-file='path/to/my.cnf' 指定按照某个配置文件进行启动

这个设置对了么？

 character_set_server=utf8

14.04用sudo apt-get install mysql-server是存在文件/etc/mysql/my.cnf的.
/usr/bin/mysql --help|grep -B 1 /etc/mysql/my.cnf
Default options are read from the following files in the given order:
/etc/my.cnf /etc/mysql/my.cnf /usr/etc/my.cnf ~/.my.cnf
后面的优先级更高,建议只保留一个配置文件/etc/mysql/my.cnf.
内容:

 #
# The MySQL database server configuration file.
#
# You can copy this to one of:
# - "/etc/mysql/my.cnf" to set global options,
# - "~/.my.cnf" to set user-specific options.
# 
# One can use all long options that the program supports.
# Run program with --help to get a list of available options and with
# --print-defaults to see which it would actually understand and use.
#
# For explanations see
# http://dev.mysql.com/doc/mysql/en/server-system-variables.html

# This will be passed to all mysql clients
# It has been reported that passwords should be enclosed with ticks/quotes
# escpecially if they contain "#" chars...
# Remember to edit /etc/mysql/debian.cnf when changing the socket location.
[client]
port        = 3306
socket      = /var/run/mysqld/mysqld.sock

# Here is entries for some specific programs
# The following values assume you have at least 32M ram

# This was formally known as [safe_mysqld]. Both versions are currently parsed.
[mysqld_safe]
socket      = /var/run/mysqld/mysqld.sock
nice        = 0

[mysqld]
#
# * Basic Settings
#
user        = mysql
pid-file    = /var/run/mysqld/mysqld.pid
socket      = /var/run/mysqld/mysqld.sock
port        = 3306
basedir     = /usr
datadir     = /var/lib/mysql
tmpdir      = /tmp
lc-messages-dir = /usr/share/mysql
skip-external-locking
#
# Instead of skip-networking the default is now to listen only on
# localhost which is more compatible and is not less secure.
bind-address        = 127.0.0.1
#
# * Fine Tuning
#
key_buffer      = 16M
max_allowed_packet  = 16M
thread_stack        = 192K
thread_cache_size       = 8
# This replaces the startup script and checks MyISAM tables if needed
# the first time they are touched
myisam-recover         = BACKUP
#max_connections        = 100
#table_cache            = 64
#thread_concurrency     = 10
#
# * Query Cache Configuration
#
query_cache_limit   = 1M
query_cache_size        = 16M
#
# * Logging and Replication
#
# Both location gets rotated by the cronjob.
# Be aware that this log type is a performance killer.
# As of 5.1 you can enable the log at runtime!
#general_log_file        = /var/log/mysql/mysql.log
#general_log             = 1
#
# Error log - should be very few entries.
#
log_error = /var/log/mysql/error.log
#
# Here you can see queries with especially long duration
#log_slow_queries   = /var/log/mysql/mysql-slow.log
#long_query_time = 2
#log-queries-not-using-indexes
#
# The following can be used as easy to replay backup logs or for replication.
# note: if you are setting up a replication slave, see README.Debian about
#       other settings you may need to change.
#server-id      = 1
#log_bin            = /var/log/mysql/mysql-bin.log
expire_logs_days    = 10
max_binlog_size         = 100M
#binlog_do_db       = include_database_name
#binlog_ignore_db   = include_database_name
#
# * InnoDB
#
# InnoDB is enabled by default with a 10MB datafile in /var/lib/mysql/.
# Read the manual for more InnoDB related options. There are many!
#
# * Security Features
#
# Read the manual, too, if you want chroot!
# chroot = /var/lib/mysql/
#
# For generating SSL certificates I recommend the OpenSSL GUI "tinyca".
#
# ssl-ca=/etc/mysql/cacert.pem
# ssl-cert=/etc/mysql/server-cert.pem
# ssl-key=/etc/mysql/server-key.pem



[mysqldump]
quick
quote-names
max_allowed_packet  = 16M

[mysql]
#no-auto-rehash # faster start of mysql but no tab completition

[isamchk]
key_buffer      = 16M

#
# * IMPORTANT: Additional settings that can override those from this file!
#   The files must end with '.cnf', otherwise they'll be ignored.
#
!includedir /etc/mysql/conf.d/

apt-get download mysql-common 下载这个包,里面有个这个文件.
在配置里的[mysqld]下加入:
character_set_server=utf8
另外,注意创建数据库和表时也指定编码:

 CREATE DATABASE IF NOT EXISTS mybase DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci;
USE mybase;
CREATE TABLE `posts` (
    `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
    `post_title` varchar(255) NOT NULL DEFAULT '',
    `post_content` text,
    PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=0 DEFAULT CHARSET=utf8;

连接数据库时也制定编码,比如PHP:

 <?php
$dsn = "mysql:dbname=$app[db_name];host=$app[db_host];port=$app[db_port];charset=utf8";
$dbh = new PDO($dsn, $app['db_username'], $app['db_password'], array(
    PDO::ATTR_PERSISTENT => $app['db_pconnect'],
    PDO::ATTR_EMULATE_PREPARES => false,
    PDO::MYSQL_ATTR_INIT_COMMAND => 'SET NAMES utf8'
));

页面输出也指定UTF-8编码:

 <?php
header('Content-Type: text/html; charset=utf-8');
?>
<meta charset="utf-8">

编辑器和IDE里也使用UTF-8编码,统一下来后就不会乱码了.