NAME

       oarsh - remote shell connector for OAR batch scheduler.

       oarcp - oarsh companion to copy files from a node or to a node.

SYNOPSIS

       oarsh [OPTIONS] <NODENAME> [COMMAND]

       oarcp [OPTIONS] [NODENAME:]<PATHNAME> [NODENAME:]<PATHNAME>

DESCRIPTION

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

OPTIONS

       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).

ENVIRONMENT

       OAR_JOB_ID
           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).

       OAR_JOB_KEY_FILE
           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 one 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.

       OAR_USER_CPUSET
           Setting the OAR_USER_CPUSET environment variable for oarsh allows running the process in  the  target
           node with a subset of the CPU set of the job. Expected format for OAR_USER_CPUSET is a list of , or +
           or  space  separated  processing unit. The processing unit ids of the job can be shown using oarprint
           (cpuset property), or more generally with hwloc's lstopo command (physical PU). The oarnodes  command
           also shows the cpuset resource property for every OAR resource.

       OAR_USER_GPUDEVICE
           If  the  GPU  device  mechanism  is  enabled  in the OAR installation, setting the OAR_USER_GPUDEVICE
           environment variable for oarsh allows running the process in the target node with a subset of the GPU
           devices of the job. Expected format for OAR_USER_GPUDEVICE is a list of , or  +  or  space  separated
           Linux  char devices (e.g.: /dev/nvidia0). The GPU devices of the job can be shown with using oarprint
           (gpudevice property). The oarnodes command also shows the gpudevice resource property for  every  OAR
           resource.

EXAMPLES

       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, possibly from anywhere:
            OAR_JOB_KEY_FILE=~/my_key oarsh node-23

       Same thing but using OpenSSH-like -i option:
            oarsh -i ~/my_key node-23

       Running a process on a subset of the CPU set of GPU devices of the job:
            OAR_USER_CPUSET=0,7 OAR_USER_GPUDEVICE=/dev/nvidia3 oarsh node-23

NOTES

       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.

       When a job is running alone on a whole host, it may be possible to simply use ssh  instead  of  oarsh  to
       connect to the host. This require OAR to be configured with the pam_oar_adopt mechanism.

SEE ALSO

       oarprint(1), oarnodes(1), lstopo(1), ssh(1), oarcp(1), oarsub(1), pam_oar_adopt(8)

COPYRIGHTS

        Copyright 2003-2025 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.

oarsh                                              2025-03-24                                           oarsh(1)