liuyan@ubuntu:/etc/init.d$ sudo apt-get install openssh-server -y
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
openssh-server : Depends: openssh-client (= 1:7.2p2-4)
Depends: openssh-sftp-server but it is not going to be installed
Recommends: ssh-import-id but it is not going to be installed
E: Unable to correct problems, you have held broken packages.
解决办法：
1、安装指定版本的 openssh -client
sudo apt-get install openssh-client=1:7.2p2-4
2、再次安装openssh-server
sudo apt-get install openssh-server