环境：redhat6.5+mysql5.6.21
[root@linfytest2 bin]# cat /etc/redhat-release
Red Hat Enterprise Linux Server release 6.5 (Santiago)
[root@linfytest2 bin]# ./mysqld --version
./mysqld Ver 5.6.21 for Linux on x86_64 (Source distribution)

mysqld_multi的样例：
[root@linfytest2 bin]# ./mysqld_multi --example
# This is an example of a my.cnf file for mysqld_multi.
# Usually this file is located in home dir ~/.my.cnf or /etc/my.cnf
#
# SOME IMPORTANT NOTES FOLLOW:
#
# 1.COMMON USER
#
#Make sure that the MySQL user, who is stopping the mysqld services, has
#the same password to all MySQL servers being accessed by mysqld_multi.
#This user needs to have the 'Shutdown_priv' -privilege, but for security
#reasons should have no other privileges. It is advised that you create a
#common 'multi_admin' user for all MySQL servers being controlled by
#mysqld_multi. Here is an example how to do it:
#
#GRANT SHUTDOWN ON *.* TO multi_admin@localhost IDENTIFIED BY 'password'
#
#You will need to apply the above to all MySQL servers that are being
#controlled by mysqld_multi. 'multi_admin' will shutdown the servers
#using 'mysqladmin' -binary, when 'mysqld_multi stop' is being called.
#
# 2.PID-FILE
#
#If you are using mysqld_safe to start mysqld, make sure that every
#MySQL server has a separate pid-file. In order to use mysqld_safe
#via mysqld_multi, you need to use two options:
#
#mysqld=/path/to/mysqld_safe
#ledir=/path/to/mysqld-binary/
#
#ledir (library executable directory), is an option that only mysqld_safe
#accepts, so you will get an error if you try to pass it to mysqld directly.
#For this reason you might want to use the above options within [mysqld#]
#group directly.
#
# 3.DATA DIRECTORY
#
#It is NOT advised to run many MySQL servers within the same data directory.
#You can do so, but please make sure to understand and deal with the
#underlying caveats. In short they are:
#- Speed penalty
#- Risk of table/data corruption
#- Data synchronising problems between the running servers
#- Heavily media (disk) bound
#- Relies on the system (external) file locking
#- Is not applicable with all table types. (Such as InnoDB)
# Trying so will end up with undesirable results.
#
# 4.TCP/IP Port
#
#Every server requires one and it must be unique.
#
# 5.[mysqld#] Groups
#
#In the example below the first and the fifth mysqld group was
#intentionally left out. You may have 'gaps' in the config file. This
#gives you more flexibility.
#
# 6.MySQL Server User
#
#You can pass the user=... option inside [mysqld#] groups. This
#can be very handy in some cases, but then you need to run mysqld_multi
#as UNIX root.
#
# 7.A Start-up Manage Script for mysqld_multi
#
#In the recent MySQL distributions you can find a file called
#mysqld_multi.server.sh. It is a wrapper for mysqld_multi. This can
#be used to start and stop multiple servers during boot and shutdown.
#
#You can place the file in /etc/init.d/mysqld_multi.server.sh and
#make the needed symbolic links to it from various run levels
#(as per Linux/Unix standard). You may even replace the
#/etc/init.d/mysql.server script with it.
#
#Before using, you must create a my.cnf file either in /usr/local/mysql/my.cnf
#or /root/.my.cnf and add the [mysqld_multi] and [mysqld#] groups.
#
#The script can be found from support-files/mysqld_multi.server.sh
#in MySQL distribution. (Verify the script before using)
#


[mysqld_multi]
mysqld = /usr/local/mysql/bin/mysqld_safe
mysqladmin = /usr/local/mysql/bin/mysqladmin
user= multi_admin
password= my_password


[mysqld2]
socket = /tmp/mysql.sock2
port= 3307
pid-file= /usr/local/mysql/data2/hostname.pid2
datadir= /usr/local/mysql/data2
language= /usr/local/mysql/share/mysql/english
user= unix_user1


[mysqld3]
mysqld = /path/to/mysqld_safe
ledir = /path/to/mysqld-binary/
mysqladmin = /path/to/mysqladmin
socket = /tmp/mysql.sock3
port= 3308
pid-file= /usr/local/mysql/data3/hostname.pid3
datadir= /usr/local/mysql/data3
language= /usr/local/mysql/share/mysql/swedish
user= unix_user2


[mysqld4]
socket = /tmp/mysql.sock4
port= 3309
pid-file= /usr/local/mysql/data4/hostname.pid4
datadir= /usr/local/mysql/data4
language= /usr/local/mysql/share/mysql/estonia
user= unix_user3

[mysqld6]
socket = /tmp/mysql.sock6
port= 3311
pid-file= /usr/local/mysql/data6/hostname.pid6
datadir= /usr/local/mysql/data6
language= /usr/local/mysql/share/mysql/japanese
user= unix_user4

1、分别创建端口为3306和3307的数据库


2、创建参数文件my_multi.cnf
[mysqld_multi]
mysqld = /usr/local/mysql/bin/mysqld_safe
mysqladmin = /usr/local/mysql/bin/mysqladmin
log = /var/lib/mysql/mysqld_multi.log
user = multi_admin
password = 111111

[mysqld6]
datadir = /var/lib/mysql3306
pid-file = /var/lib/mysql3306/mysqld.pid
socket = /tmp/mysql3306.sock
port = 3306

[mysqld7]
datadir = /var/lib/mysql3307
socket = /tmp/mysql3307.sock
pid-file = /var/lib/mysql3307/mysqld.pid
port = 3307

3、启动
[root@linfytest2 bin]# ./mysqld_multi --defaults-extra-file=/etc/my_multi.cnf report
Reporting MySQL servers
MySQL server from group: mysqld6 is not running
MySQL server from group: mysqld7 is not running

[root@linfytest2 bin]# ./mysqld_multi --defaults-extra-file=/etc/my_multi.cnf start
[root@linfytest2 bin]# ./mysqld_multi --defaults-extra-file=/etc/my_multi.cnf report
Reporting MySQL servers
MySQL server from group: mysqld6 is running
MySQL server from group: mysqld7 is running

[root@linfytest2 bin]# netstat -tunlp|grep mysql
tcp0 0 :::3306 :::*LISTEN 17982/mysqld
tcp0 0 :::3307 :::*LISTEN 17983/mysqld


4、停止
[root@linfytest2 bin]# ./mysqld_multi --defaults-extra-file=/etc/my_multi.cnf stop
[root@linfytest2 bin]# ./mysqld_multi --defaults-extra-file=/etc/my_multi.cnf report
Reporting MySQL servers
MySQL server from group: mysqld6 is not running
MySQL server from group: mysqld7 is not running