To be able to run the TELEMAC system in parallel on a network of computers via MPI, one has to be able to log in to any of the machines without having to enter a password. This can be done easily with ssh keys. This article describes the methodology to setup password less login vi ssh for MPI applications.

Principle of key authentication

The principle of key authentication is the following. A keypair consists of private key and a public key

More info on wikipedia.

Key generation on master

ssh-keygen -t dsa

Note: if your network of computers for the parallel computations is on a safe private network, you can consider using a blank key. However, this is not recommended and using ssh-agent with a long key is usually the preferred option.

Copy the key to the slaves

scp .ssh/id_dsa.pub login@slave01: ssh slave01 mkdir .ssh chmod 0600 .ssh cat id_dsa.pub > .ssh/authorized_keys rm -f id_dsa.pub

Now go back to the master node and try to log into slave01. You should be asked for the key this time: ssh login@slave01

Advanced features

ssh-agent or using a blank key?

ssh-agent running ssh-add

master$ ssh login@slave1 slave01$

List of keys to use

from "master, slave01, slave02" sdvkms;dflmk

Configure ssh for MPI

Contents