User guide

3–InfiniBand
®
Cluster Setup and Administration
Host Environment Setup for MPI
IB0054606-02 A 3-43
At this point, any end user should be able to login to the ip-fe front end system
and use
ssh to login to any IB node without being prompted for a password or
pass phrase.
Configuring for ssh Using ssh-agent
The ssh-agent, a daemon that caches decrypted private keys, can be used to
store the keys. Use
ssh-add to add your private keys to ssh-agent’s cache.
When
ssh establishes a new connection, it communicates with ssh-agent to
acquire these keys, rather than prompting you for a passphrase.
The process is described in the following steps:
1. Create a key pair. Use the default file name, and be sure to enter a
passphrase.
$ ssh-keygen -t rsa
2. Enter a passphrase for your key pair when prompted. Note that the key
agent does not survive X11 logout or system reboot:
$ ssh-add
3. The following command tells ssh that your key pair should let you in:
$ cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
Edit the ~/.ssh/config file so that it reads like this:
Host*
ForwardAgent yes
ForwardX11 yes
CheckHostIP no
StrictHostKeyChecking no
This file forwards the key agent requests back to your desktop. When you
log into a front end node, you can use
ssh to compute nodes without
passwords.
4. Follow your administrator’s cluster policy for setting up
ssh-agent on the
machine where you will be running
ssh commands. Alternatively, you can
start the
ssh-agent by adding the following line to your ~/.bash_profile
(or equivalent in another shell):
eval ‘ssh-agent‘
Use back quotes rather than single quotes. Programs started in your login
shell can then locate the
ssh-agent and query it for keys.