Ssh – Open MPI can’t launch remote nodes via SSH

clusterhpcssh

I am trying to set up Open MPI between a few machines on out network.
Open MPI works fine locally, but I just can't get it to work on a remote node.
I can ssh into the remote machine (without password) just fine, but if I try something like

mpiexec -n 4 --host remote.host hello_c

then the ssh connection just times out.

I checked several tutorials but the only configuration instructions they give is "make sure you can ssh into the remote machine without a password". I did and I still can't launch nodes on remote machines. What's the problem?

Best Answer

From the remote machine are you able to ssh to other machines and localhost without password? If not, you may not have copied over your private key. Are your systems running something like SELinux or AppArmor? For SELinux you can run 'setenforce 0' to disable it so you can test.

Related Solutions

SSH Authentication – Use Only Password and Ignore SSH Key

Try ssh -o PasswordAuthentication=yes -o PreferredAuthentications=keyboard-interactive,password -o PubkeyAuthentication=no host.example.org

In ssh v2, keyboard-interactive is another way to say "password". The -o PubkeyAuthentication=no option instructs the client not to attempt key pair authentication.

In addition, the PasswordAuthentication=yes option is to override any previously configured ssh options that may have disabled it.

Run Local Bash Script on Remote Machines via SSH – Step-by-Step Guide

You can pass a script and have it execute ephemerally by piping it in and executing a shell.

e.g.

echo "ls -l; echo 'Hello World'" | ssh me@myserver /bin/bash

Naturally, the "ls -l; echo 'Hello World'" part could be replaced with a bash script stored in a file on the local machine.

e.g.

cat script.sh | ssh me@myserver /bin/bash

Cheers!

Best Answer

Related Solutions

SSH Authentication – Use Only Password and Ignore SSH Key

Run Local Bash Script on Remote Machines via SSH – Step-by-Step Guide

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