Jean Zay: Access and shells

Connection to the Jean Zay front end is done via ​ssh from a machine registered at IDRIS:

$ ssh my_idris_login@jean-zay.idris.fr

Then, enter your password if you have not configured the ​ssh key.

The jean-zay front end is the only machine which is visible and directly accessible by the users and offers the following functionalities: interactive connection, compilation for the other nodes of the cluster, preparation, submission and monitoring of your jobs with the batch manager, Slurm. Parallel jobs must be executed from the front-end via the ​Slurm batch manager.

Interactive connection to the pre-/post-processing front end is done by ssh from a machine registered at IDRIS:

$ ssh my_idris_login@jean-zay-pp.idris.fr

Then, enter your password if you have not configured the ssh key.

The pre-/post-processing architecture installed at IDRIS consists of four HPE machines: each equipped with 3 TiB of memory, two Intel Cascade Lake 6132 12-core processors and a Nvidia V100 GPU. The ​jean-zay-pp​ front end offers the following functionalities: interactive connection, compilation, preparation, submission and monitoring of your jobs with the ​Slurm batch manager.

To use the pre- and post-processing nodes in batch, it is sufficient to specify the prepost partition when preparing a job, whether you are using the jean-zay or the jean-zay-pp front end.

Connections ​by SSH keys (private key / public key) are authorised ​at IDRIS.

ATTENTION: we plan to strengthen our security policy regarding access to the jean-zay machine. Therefore, we ask you to test, as of now, the use of certificates for your SSH connections instead of the usual SSH key pairs (private key / public key) by following the detailled procedures here.

With the objective of reinforcing the security when accessing Jean Zay, we ask you to test the use of certificates for your SSH connections instead of the usual public/private SSH key pairs. The creation and use of certificates are done by respecting the detailled procedures here.

During the test phase, connections via classic SSH keys will remain possible. Please let us know of any problems you may encounter with the use of certificates.

Your ​$HOME space is common to all the Jean-Zay front ends.​ Consequently, every modification of your personal environment files is automatically applied on all the machines.

The Bourne Again shell (bash) is the only login shell available on the IDRIS machines: IDRIS does not guarantee that the default user environment will be correctly defined with other shells. The bash is an important evolution of the Bourne shell (formerly sh) with advanced functionalities. However, other shells (​ksh,​ ​tcsh,​ ​csh​) are also installed on the machines to allow the execution of scripts which are using them.

The .bash_profile, if it exists in your HOME, is executed at the login only one time per session. If not, it is the .profile file which is executed, if it exists. The environment variables and the programs are placed in one of these files, to be launched at the connection. Aliases, personal functions and the loading of modules are to be placed in the .bashrc file which, in contrast, is run at the launching of each sub-shell.

It is preferable to use only one environment file: .bash_profile or .profile. Caution: Overwriting the PATH variable inevitably leads to major problems. For this reason, it is always advised to keep the PATH provided by the machine. If you wish to add a research directory for the execution of local commands during all your future sessions, you must proceed in the following way in your .bash_profile or .profile :

$ export PATH=$PATH:directory_to_add

The bash proposes two edition modes; you may choose the one you prefer by using the set command:

$ set -o emacs # to be in emacs mode
$ set -o vi # to be in vi mode