由于用到centos 5.11,而yum mysql的版本是5.09 要想实现主从复制，就得升级到5.5以上。
yum 升级比较方便。操作如下：
系统环境：centos5.5
centos5.5的源mysql目前还停留在5.0.19上，要做数据库主从的时候，必须升级到5.1以上。
索性，直接到5.5吧
1、安装MySQL 5.5.x的yum源：
rpm -Uvh http://repo.webtatic.com/yum/centos/5/latest.rpm
2、安装MySQL客户端的支持包：
yum install libmysqlclient15 --enablerepo=webtatic
3、卸载MySQL老版本的软件包：
yum remove mysql mysql-*
4、安装MySQL 5.5的客户端和服务端：
yum install mysql55 mysql55-server --enablerepo=webtatic
5、启动MySQL系统服务，更新数据库：
/etc/init.d/mysqld restart
mysql_upgrade
升级完毕
1. /etc/init.d/mysqld restart
2. 停止 mysqld： [确定]
3. 初始化 MySQL 数据库： Installing MySQL system tables...
4. OK
5. Filling help tables...
6. OK
7.
8. To start mysqld at boot time you have to copy
9. support-files/mysql.server to the right place for
10.
11. PLEASE REMEMBER TO SET A PASSWORD FOR THE MySQL root USER !
12. To do
13.
14. /usr/bin/mysqladmin -u root password 'new-password'
15. /usr/bin/mysqladmin -u root -h client4.360zan.cn password 'new-password'
16.
17. Alternatively you can run:
18. /usr/bin/mysql_secure_installation
19.
20. which will also give you the option of removing the test
21. databases and anonymous user created by default. This is
22. strongly recommended for
23.
24. See the manual for
25.
26. You can start the MySQL daemon with:
27. cd /usr ; /usr/bin/mysqld_safe &
28.
29. You can test the MySQL daemon with mysql-test-run.pl
30. cd /usr/mysql-test ; perl mysql-test-run.pl
31.
32. Please report any problems with the /usr/bin/mysqlbug script!
33.
34. [确定]
35. 启动 mysqld： [确定]
源是国外的，贼慢贼慢。
