错误一：

[root@localhost opt]# rsync -avz backuper@192.168.7.128::wwwroot /opt
@ERROR: access denied to wwwroot from unknown (192.168.7.129)
rsync error: error starting client-server protocol (code 5) at main.c(1516) [Receiver=3.0.9]

解决办法
检查同步源rsync的配置文件hosts allow是否开放了目标的IP地址段
错误二：

[root@localhost opt]# rsync -avz backuper@192.168.7.128::wwwroot /opt
rsync: failed to connect to 192.168.7.128 (192.168.7.128): No route to host (113)
rsync error: error in socket IO (code 10) at clientserver.c(122) [Receiver=3.0.9]

解决办法
检查防火墙规则是否增加了873端口，或者直接关闭防火墙
错误三：

[root@localhost opt]# rsync -avz backuper@192.168.7.128::wwwroot /opt
Password: 
@ERROR: auth failed on module wwwroot
rsync error: error starting client-server protocol (code 5) at main.c(1516) [Receiver=3.0.9]

解决办法
检查同步源rsync的配置文件的secrets file账号密码文件名或者路径是否异常