在第一次使用rsync同步文件时，提示确认服务器真实性
The authenticity of host can't be established.
This key is not known by any other names
Are you sure you want to continue connecting (yes/no/[fingerprint])?回复yes，选择，将服务器公钥保存到本地已知列表（之后不再提醒）。
之后回复
warning: Permanently added '' (ED25519) to the list of known hosts.
Connection closed by port 22
rsync: connection unexpectedly closed (0 bytes received so far) [Receiver]
rsync error: unexplained error (code 255) at io.c(232) [Receiver=3.2.7]现在本地已生成.ssh/known_hosts文件
再次输入rsync同步命令，在提示输入密码时输入即可。