oarsh(1) remote shell connector for OAR batch scheduler.





Connect to a node from the job submission frontend of the cluster or any other node.


The oarsh mechanism uses OpenSSH client (the ssh command) under the hood to perform connections to remote hosts. Thus most of OpenSSH options can be used (but some are filtered out for security reasons).


If not using the job-key mechanism, the OAR_JOB_ID environment variable has to be set to give the jobid of the job to connect to on the remote node (a node can run several jobs at a same time). This is only required for connecting from outside the job (e.g. from the job submission frontend).
If using the job-key mechanism (see oarsub -k -e/-i), oarsh can use the job-key defined by the OAR_JOB_KEY_FILE environment variable to connect to job on the remote machine. That mechanism can allow to connect to a job from a machine which is outside the OAR cluster the job belong to (e.g. in a grid of OAR clusters), given the job-key is available on that machine. NB: it is also possible to give the job-key using oarsh -i option.


Connecting from within our job, from one node to another one (node23):
> oarsh node-23
Connecting to a node (node23) of our job (Id: 4242) from the frontal of the cluster:
> OAR_JOB_ID=4242 oarsh node-23
Connecting to a node (node23) of our job that was submitted using a job-key:
> OAR_JOB_KEY_FILE=~/my_key oarsh node-23
Same thing but using OpenSSH-like -i option:
> oarsh -i ~/my_key node-23


oarsh inherits from most of OpenSSH capabilities (e.g. X11 forwarding). However, one feature which oarsh does break is the SSH Agent.

The user's OpenSSH configuration files (files in the ~/.ssh directory) are not used by oarsh.

For advanced users, when using the job-key mechanism, it is also possible to use ssh directly to connect to a job on a node. Please refer to the documentation of your cluster, or ask the admisitrator of your cluster.


 Copyright 2003-2016 Laboratoire d'Informatique de Grenoble (http://www.liglab.fr). This software is licensed under the GNU General Public License Version 2 or above. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.