排除故障 
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1.@ERROR: auth failed on module xxxxx
    rsync: connection unexpectedly closed (90 bytes read so far)
    rsync error: error in rsync protocol data stream (code 12) at io.c(150)
    这是因为密码设错了, 无法登入成功, 请检查一下 rsyncd.scrt 中的密码, 二端是否一致? 

2.password file must not be other-accessible 
    continuing without password file 
    Password:
    这表示 rsyncd.scrt 的档案权限属性不对, 应设为 600。

3.@ERROR: chroot failed
    rsync: connection unexpectedly closed (75 bytes read so far)
    rsync error: error in rsync protocol data stream (code 12) at io.c(150)   
    这通常是您的 rsyncd.conf 中的 path 路径所设的那个目录并不存在所致.请先用 mkdir开设好要备份目录

4.@ERROR: access denied to www from unknown (192.168.1.123)
    rsync: connection unexpectedly closed (0 bytes received so far) [receiver]
    rsync error: error in rsync protocol data stream (code 12) at io.c(359)
    最后原因终于找到了。因为有两个网段都需要同步该文件夹内容,但没有在hosts allow 后面添加另一个IP段
    hosts allow = 192.168.1.0/24
    改为
    hosts allow = 192.168.1.0/24 192.168.2.0/24
    重新启动rsync服务,问题解决 

5.rsync: failed to connect to 172.21.50.8: No route to host (113)
    rsync error: error in socket IO (code 10) at clientserver.c(104) [receiver=2.6.9]
    对方没开机、防火墙阻挡、通过的网络上有防火墙阻挡,都有可能。关闭防火墙,其实就是把tcp udp 的873端口打开
    启动服务:rsync --daemon --config=/etc/rsyncd.conf

6.@ERROR: auth failed on module backup
    rsync error: error starting client-server protocol (code 5) at main.c(1506) [Receiver=3.0.7]
    client端没有设置/etc/rsync.pas这个文件,而在使用rsync命令的时候,加了这个参数--password-file=/etc/rsync.scrt 

7.rsync: recv_generator: mkdir "/teacherclubBackup/rsync……" failed: No space left on device (28)
    *** Skipping any contents from this failed directory ***
    磁盘空间满了 

8.rsync: opendir "/kexue" (in dtsChannel) failed: Permission denied (13)
    同步目录的权限设置不对,改为755 

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