1.1 rsync客户端执行rsync命令错误：
客户端的错误现象：
[root@nfs01 tmp]# rsync -avz /etc/hosts rsync_backup@172.16.1.41::/backup
ERROR: The remote path must start with a module name not a /
rsync error: error starting client-server protocol (code 5) at main.c(1503) [sender=3.0.6]
异常问题解决：
rsync命令语法理解错误，::/backup是错误的语法，应该为::backup(rsync模块)
1.2 @ERROR: auth failed on module oldboy
客户端的错误现象：
[root@nfs01 tmp]# rsync -avz /etc/hosts rsync_backup@172.16.1.41::backup
Password:
@ERROR: auth failed on module backup
rsync error: error starting client-server protocol (code 5) at main.c(1503) [sender=3.0.6]
异常问题解决：
1. 密码真的输入错误，用户名真的错误
2. secrets file = /etc/rsync.password指定的密码文件和实际密码文件名称不一致
3. /etc/rsync.password文件权限不是600
4. rsync_backup:123456密码配置文件后面注意不要有空格
echo "rsync_backup:123456" >>/etc/rsync.password
rsync客户端密码文件中只输入密码信息即可，不要输入虚拟认证用户名称
1.3 Unknown module 'backup'
[root@nfs01 tmp]# rsync -avz /etc/hosts rsync_backup@172.16.1.41::backup
@ERROR: Unknown module 'backup'
rsync error: error starting client-server protocol (code 5) at main.c(1503) [sender=3.0.6]
异常问题解决：
1. /etc/rsyncd.conf配置文件模块名称书写错误
1.4 Permission denied
[root@nfs01 tmp]# rsync -avz /etc/hosts rsync_backup@172.16.1.41::backup
Password:
sending incremental file list
hosts
rsync: mkstemp ".hosts.5z3AOA" (in backup) failed: Permission denied (13)
sent 196 bytes received 27 bytes 63.71 bytes/sec
total size is 349 speedup is 1.57
rsync error: some files/attrs were not transferred (see previous errors) (code 23) at main.c(1039) [sender=3.0.6]
异常问题解决：
1. 共享目录的属主和属组不正确，不是rsync
2. 共享目录的权限不正确，不是755
1.5 chdir failed
[root@nfs01 tmp]# rsync -avz /etc/hosts rsync_backup@172.16.1.41::backup
Password:
@ERROR: chdir failed
rsync error: error starting client-server protocol (code 5) at main.c(1503) [sender=3.0.6]
异常问题解决：
1. 备份存储目录没有建立
2. 建立的备份存储目录和配置文件定义不一致
说明：如果没有备份存储目录
1.6 invalid uid rsync
[root@nfs01 tmp]# rsync -avz /etc/hosts rsync_backup@172.16.1.41::backup
Password:
@ERROR: invalid uid rsync
rsync error: error starting client-server protocol (code 5) at main.c(1503) [sender=3.0.6]
异常问题解决：
rsync服务对应rsync虚拟用户不存在了
1.7 客户端已经配置了密码文件，但免秘钥登录方式，依旧需要输入密码
password file must not be other-accessible
[root@nfs01 tmp]# rsync -avz /etc/hosts rsync_backup@172.16.1.41::backup --password-file=/etc/rsync.password
password file must not be other-accessible
continuing without password file
Password:
sending incremental file list
sent 26 bytes received 8 bytes 5.23 bytes/sec
total size is 349 speedup is 10.26
异常问题解决：
rsync客户端的秘钥文件也必须是600权限
1.8 rsync客户端连接慢问题
错误日志输出
2017/03/08 20:14:43 [3422] params.c:Parameter() - Ignoring badly formed line in configuration file: ignore errors
2017/03/08 20:14:43 [3422] name lookup failed for 172.16.1.31: Name or service not known
2017/03/08 20:14:43 [3422] connect from UNKNOWN (172.16.1.31)
2017/03/08 20:14:43 [3422] rsync to backup/ from rsync_backup@unknown (172.16.1.31)
2017/03/08 20:14:43 [3422] receiving file list
2017/03/08 20:14:43 [3422] sent 76 bytes received 83 bytes total size 349
正确日志输出
2017/03/08 20:16:45 [3443] params.c:Parameter() - Ignoring badly formed line in configuration file: ignore errors
2017/03/08 20:16:45 [3443] connect from nfs01 (172.16.1.31)
2017/03/08 20:16:45 [3443] rsync to backup/ from rsync_backup@nfs02 (172.16.1.31)
2017/03/08 20:16:45 [3443] receiving file list
2017/03/08 20:16:45 [3443] sent 76 bytes received 83 bytes total size 349
异常问题解决：
查看日志进行分析
10 rsync服务没有正确启动
Connection refused (111)
[root@oldboy-muban ~]# rsync -avz /etc/hosts rsync_backup@172.16.1.41::backup
rsync: failed to connect to 172.16.1.41: Connection refused (111)
rsync error: error in socket IO (code 10) at clientserver.c(124) [sender=3.0.6]
解决 rsync服务没开启
[root@oldboy-muban ~]# rsync --daemon
[root@oldboy-muban ~]# ss -lntup |grep rsync
tcp LISTEN 0 5 :::873 :::* users:(("rsync",1434,5))
tcp LISTEN 0 5 *:873 *:* users:(("rsync",1434,4))
[root@oldboy-muban ~]# rsync -avz /etc/hosts rsync_backup@172.16.1.41::backup
Password:
sending incremental file list
hosts
sent 196 bytes received 27 bytes 49.56 bytes/sec
total size is 349 speedup is 1.57