[mysqld_multi]
 mysqld     = /usr/bin/mysqld_safe
 mysqladmin = /usr/bin/mysqladmin
 
 [mysqld1]
 port            = 3307
 pid-file        = /var/run/mysqld/db-app1.pid
 datadir         = /var/lib/mysql
 socket          = /var/run/mysqld/mysql.sock1
 user            = mysql
 log_error       = /tmp/mysql1.log
[mysqld2]
port            = 3305
pid-file        = /var/run/mysqld/db-app2.pid
datadir         = /var/lib/mysql2
socket          = /var/run/mysqld/mysql.sock2
user            = mysql
log_error       = /var/mysql2.log

[email protected] ~/桌面 $ ps -ef | grep mysql
mysql     1019     1  0 21:27 ?        00:00:00 /usr/sbin/mysqld
bells     1828  1761  0 21:28 pts/0    00:00:00 grep --colour=auto mysql
[email protected] ~/桌面 $ sudo /etc/init.d/mysql stop
[sudo] password for bells:
Rather than invoking init scripts through /etc/init.d, use the service(8)
utility, e.g. service mysql stop

Since the script you are attempting to invoke has been converted to an
Upstart job, you may also use the stop(8) utility, e.g. stop mysql
mysql stop/waiting
[email protected] ~/桌面 $ ps -ef | grep mysql
bells     1850  1761  0 21:28 pts/0    00:00:00 grep --colour=auto mysql
[email protected] /tmp $ sudo mysqld_multi start 1,2
[email protected] /tmp $ ps -ef | grep mysql
root      1864     1  0 21:29 pts/0    00:00:00 /bin/sh /usr/bin/mysqld_safe --port=3307 --pid-file=/var/run/mysqld/db-app1.pid --datadir=/var/lib/mysql --socket=/var/run/mysqld/mysql.sock1 --user=mysql --log_error=/tmp/mysql1.log
mysql     2121  1864  1 21:29 pts/0    00:00:00 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --log_error=/tmp/mysql1.log --pid-file=/var/run/mysqld/db-app1.pid --socket=/var/run/mysqld/mysql.sock1 --port=3307
bells     2146  1761  0 21:29 pts/0    00:00:00 grep --colour=auto mysql
[email protected] /tmp $ ls
keyring-gHHfpn  mysql2.log          pulse-PKdhtXMmr18n    virtual-bells.5ENcZa
mintUpdate      pulse-2L9K88eMlGn7  ssh-eQiJHAQu1519
mysql1.log      pulse-Ob9vyJcXyHZz  unity_support_test.1
[email protected] /tmp $ sudo cat mysql1.log
120319 21:29:17 [Note] Plugin 'FEDERATED' is disabled.
120319 21:29:17  InnoDB: Initializing buffer pool, size = 8.0M
120319 21:29:17  InnoDB: Completed initialization of buffer pool
120319 21:29:17  InnoDB: Started; log sequence number 0 44233
120319 21:29:17 [Note] Event Scheduler: Loaded 0 events
120319 21:29:17 [Note] /usr/sbin/mysqld: ready for connections.
Version: '5.1.58-1ubuntu1'  socket: '/var/run/mysqld/mysql.sock1'  port: 3307  (Ubuntu)
[email protected] /tmp $ sudo cat mysql2.log
120319 21:29:17 [Note] Plugin 'FEDERATED' is disabled.
/usr/sbin/mysqld: Can't find file: './mysql/plugin.frm' (errno: 13)
120319 21:29:17 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it.
120319 21:29:17  InnoDB: Initializing buffer pool, size = 8.0M
120319 21:29:17  InnoDB: Completed initialization of buffer pool
120319 21:29:17  InnoDB: Operating system error number 13 in a file operation.
InnoDB: The error means mysqld does not have the access rights to
InnoDB: the directory.
InnoDB: File name ./ibdata1
InnoDB: File operation call: 'open'.
InnoDB: Cannot continue operation.
[email protected] /tmp $ mysqld_multi report
WARNING: Log file disabled. Maybe directory or file isn't writable?
mysqld_multi log file version 2.16; run: 一  3月 19 21:35:22 2012
Reporting MySQL servers
MySQL server from group: mysqld1 is running
MySQL server from group: mysqld2 is not running