安装SSH 报错 Privilege separation user sshd does not exist解决办法

add following line in /etc/passwd 

sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin 

其中/var/empty/sshd修改为你自己的sshd所在目录，默认一般是/usr/local/sbin/sshd