现想要在这家的服务器上安装Mysql集群，发现之前安装操作系统的时候顺便把MySql默认安装，所以需要将它先卸载掉。
1,查找已安装的mysql版本
[root@leader ~]# rpm -qa|grep mysql
qt-mysql-4.6.2-28.el6_5.x86_64
mysql-server-5.1.73-3.el6_5.x86_64
mysql-libs-5.1.73-3.el6_5.x86_64
mysql-devel-5.1.73-3.el6_5.x86_64
mysql-connector-odbc-5.1.5r1144-7.el6.x86_64
mysql-5.1.73-3.el6_5.x86_64
2.查看mysql运行状态及mysql版本信息和进程信息
[root@leader ~]# service mysqld status
mysqld (pid 20327) is running...
[root@leader ~]# mysql --version
mysql Ver 14.14 Distrib 5.1.73, for redhat-linux-gnu (x86_64) using readline 5.1
[root@leader ~]# ps -aux|grep mysql
Warning: bad syntax, perhaps a bogus '-'? See /usr/share/doc/procps-3.2.8/FAQ
root 20219 0.0 0.0 108204 1448 pts/0 S 05:56 0:00 /bin/sh /usr/bin/mysqld_safe --datadir=/var/lib/mysql --socket=/var/lib/mysql/mysql.sock --pid-file=/var/run/mysqld/mysqld.pid --basedir=/usr --user=mysql
mysql 20327 0.0 1.3 377852 25344 pts/0 Sl 05:56 0:06 /usr/libexec/mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --log-error=/var/log/mysqld.log --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock
root 21575 0.0 0.0 103252 840 pts/3 S+ 11:47 0:00 grep mysql
[root@leader ~]# chkconfig --list mysqld
mysqld 0:off 1:off 2:off 3:off 4:off 5:off 6:off
3.卸载mysql
3.1 停止mysql运行
[root@leader ~]# service mysqld stop
Stopping mysqld: [ OK ]
[root@leader ~]# service mysqld status
mysqld is stopped
3.2卸载mysql,根据rpm qa结果数进行，打印信息忽略。
[root@leader ~]# yum -y remove qt-mysql-4.6.2-28.el6_5.x86_64
[root@leader ~]# yum -y remove mysql-server-5.1.73-3.el6_5.x86_64
[root@leader ~]# yum -y remove mysql-libs-5.1.73-3.el6_5.x86_64
[root@leader ~]# yum -y remove mysql-devel-5.1.73-3.el6_5.x86_64
[root@leader ~]# yum -y remove mysql-connector-odbc-5.1.5r1144-7.el6.x86_64
[root@leader ~]# yum -y remove mysql-5.1.73-3.el6_5.x86_64
3.3执行上述命令后，验证检查结果
[root@leader ~]# rpm -qa|grep mysql
[root@leader ~]# service mysqld status
mysqld: unrecognized service
卸载后/var/lib/mysql中的数据及/etc/my.cnf不会删除，如果确定没用后就手工删除
[root@leader ~]#rm -f /etc/my.cnf
[root@leader ~]#rm -rf /var/lib/mysql
通过下面命令看看是否还有没有删的安装路径
[root@leader ~]# whereis mysql
mysql:
[root@leader ~]# find / -name mysql
/root/mysql