[Hadoop] Ubuntu localhost: ssh: connect to host localhost port 22: Connection refused

问题描述

在Ubuntu下启动hadoop的hdfs时出现：

hadoop@ubuntu:~/hadoop-2.8.1$ sbin/start-dfs.sh Starting namenodes on [localhost]localhost: ssh: connect to host localhost port 22: Connection refusedlocalhost: ssh: connect to host localhost port 22: Connection refused...

检查是否安装 openssh-server

$ ps -e | grep ssh$

没有出现任何进程，则用apt-get安装 openssh-server，出现以下提示：

hadoop@ubuntu:~/hadoop-2.8.1$ sudo apt-get install openssh-serverReading package lists... DoneBuilding dependency tree       Reading state information... DoneSome packages could not be installed. This may mean that you haverequested an impossible situation or if you are using the unstabledistribution that some required packages have not yet been createdor 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 installedE: Unable to correct problems, you have held broken packages.

手动安装 openssh-client

根据提示，到 launchpad 下载：
https://launchpad.net/ubuntu/+source/openssh/1:7.2p2-4/+build/9584683

# 手动安装下载好的deb$ sudo dpkg -i openssh-client_7.2p2-4_amd64.deb

安装openssh-server

# 安装openssh-server$ sudo apt-get install openssh-server

测试是否安装成功

$ ssh localhost