启动mysql
第一种：
/etc/rc.d/init.d/mysqld start
/etc/rc.d/init.d/mysqld stop
第二种：使用service 启动、关闭MySQL服务
service mysql start
service mysql stop
service mysql restart
异常
service mysql start 出错
出错内容：mysql: unrecognized service或mysql: 未被识别的服务
解决方法：
[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...
Mysql启动失败
问题描述：Another MySQL daemon is already running.
原因：多个Mysql进程使用了同一个socket
解决方案一：
service mysqld stop//停止mysql
mv /var/lib/mysql/mysql.sock /var/lib/mysql/mysql.sock.bak//修改名称
service mysqld start//启动mysql
解决方案二：
ps -A //查看所有进程
killall -9 *** //杀死正在运行的mysql进程