linux - Single Node Hadoop setup in unbuntu 12.0.04 -

i'm following below steps setup ssh running hadoop in single node, but, how when running sudo apt-get install openssh-server gives me below exception trace, can shed light on this?

hduser@ubuntu:~$ sudo apt-get install openssh-server [sudo] password hduser:  reading package lists... done building dependency tree        reading state information... done 

package openssh-server not available, referred package. may mean package missing, has been obsoleted, or available source

e: package 'openssh-server' has no installation candidate 

solutions tried:

1 # update , install, no luck

sudo apt-get update sudo apt-get install openssh-server 

2# ssh, not solution issue, fyi,

which ssh gives below info,

hduser@ubuntu:~$ info /usr/bin/info 

whereas,

which sshd gives no path,

hduser@ubuntu:~$ sshd hduser@ubuntu:~$  

3 # fyi,

hduser@ubuntu:~$ ssh localhost ssh: connect host localhost port 22: connection refused hduser@ubuntu:~$  hduser@ubuntu:~$ ssh -vvv localhost openssh_5.9p1 debian-5ubuntu1.1, openssl 1.0.1 14 mar 2012 debug1: reading configuration data /etc/ssh/ssh_config debug1: /etc/ssh/ssh_config line 19: applying options * debug2: ssh_connect: needpriv 0 debug1: connecting localhost [127.0.0.1] port 22. debug1: connect address 127.0.0.1 port 22: connection refused ssh: connect host localhost port 22: connection refused 

you can try below command terminal setting ssh.

sudo apt-get install ssh