注意； 可用yum -y install mysql* 安装数据库
第一步要启动 /etc/init.d/mysqld restart 或者 service mysqld restart
如上述试验不能完成同步 请查看 iptables  selinux 是否关闭
时间是否同步 如是试验可用 hwclock -s 同步系统和bios时间一致

主服务器ip=192.168.2.170
从服务器ip=192.168.2.183
(主master) 设置ip=192.168.2.170
grant all privileges on *.* to backup@'192.168.2.183' identified by '123456';
vim /etc/my.cnf
[mysqld]
server-id = 1
log-bin = mysql-bin
保存并退出
重启服务
service mysqld restart如不想退出可用system service mysqld restart命令
show master status;

+------------------+----------+--------------+------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000004 |       98 |              |                  |
+------------------+----------+--------------+------------------+
1 row in set (0.02 sec)
（从slave）设置ip192.168.2.183
vim /etc/my.cnf
[mysqld]
server-id = 2
log-bin = mysql-bin
stop slave;（停止线程）
change master to master_host='192.168.2.170',master_user='backup',master_password='123456',master_log_file='mysql-bin.000004',master_log_pos=98;（master_log_file='mysql-bin.000004',master_log_pos=98;这个会在做得时候不同，要注意变通，这里要用到主服务器上的信息）
start slave;（从启线程）
查看
show slave status;
如显示这些内容则正确
----------------------------------+---------------+-------------+-------------+---------------+------------------+---------------------+-------------------------+---------------+-----------------------+------------------+-------------------+-----------------+---------------------+--------------------+------------------------+-------------------------+-----------------------------+------------+------------+--------------+---------------------+-----------------+-----------------+----------------+---------------+--------------------+--------------------+--------------------+-----------------+-------------------+----------------+-----------------------+
| Slave_IO_State                   | Master_Host   | Master_User | Master_Port | Connect_Retry | Master_Log_File  | Read_Master_Log_Pos | Relay_Log_File          | Relay_Log_Pos | Relay_Master_Log_File | Slave_IO_Running | Slave_SQL_Running | Replicate_Do_DB | Replicate_Ignore_DB | Replicate_Do_Table | Replicate_Ignore_Table | Replicate_Wild_Do_Table | Replicate_Wild_Ignore_Table | Last_Errno | Last_Error | Skip_Counter | Exec_Master_Log_Pos | Relay_Log_Space | Until_Condition | Until_Log_File | Until_Log_Pos | Master_SSL_Allowed | Master_SSL_CA_File | Master_SSL_CA_Path | Master_SSL_Cert | Master_SSL_Cipher | Master_SSL_Key | Seconds_Behind_Master |
+----------------------------------+---------------+-------------+-------------+---------------+------------------+---------------------+-------------------------+---------------+-----------------------+------------------+-------------------+-----------------+---------------------+--------------------+------------------------+-------------------------+-----------------------------+------------+------------+--------------+---------------------+-----------------+-----------------+----------------+---------------+--------------------+--------------------+--------------------+-----------------+-------------------+----------------+-----------------------+
| Waiting for master to send event | 192.168.2.170 | backup      |        3306 |            60 | mysql-bin.000004 |                 276 | mysqld-relay-bin.000002 |           413 | mysql-bin.000004      | Yes              | Yes               |                 |                     |                    |                        |                         |                             |          0 |            |            0 |                 276 |             413 | None            |                |             0 | No                 |                    |                    |                 |                   |                |                     0 |
+----------------------------------+---------------+-------------+-------------+---------------+------------------+---------------------+-------------------------+---------------+-----------------------+------------------+-------------------+-----------------+---------------------+--------------------+------------------------+-------------------------+-----------------------------+------------+------------+--------------+---------------------+-----------------+-----------------+----------------+---------------+--------------------+--------------------+--------------------+-----------------+-------------------+----------------+-----------------------+
1 row in set (0.00 sec)
下面做测试
在主服务器上
create database shunying；
显示Query OK, 1 row affected (0.01 sec)
在从服务上查看
show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| backup             |
| mysql              |
| shunying           |
| test               |
+--------------------+



在以上的基础上实现双向备份
在ip=192.168.2.183上操作
grant all privileges on *.* to backup@'192.168.2.170' identified by '123456';
show master status;
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id:    4
Current database: *** NONE ***

+------------------+----------+--------------+------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000002 |       98 |              |                  |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)
在192.168.2.170上做操作
stop slave;
change master to master_host='192.168.2.183',master_user='backup',master_password='123456',master_log_file='mysql-bin.000002',master_log_pos=98;
start slave;
show slave status;
测试
在ip=192.168.2.183上面
create database ying
Query OK, 1 row affected (0.00 sec)
在ip=192.168.2.170上面查看

show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| backup             |
| mysql              |
| shunying           |
| test               |
| ying               |
+--------------------+
6 rows in set (0.00 sec)