Turing, Ada, Adapp : Access and shells

Machine access

Turing :

The IBM Turing system installed at IDRIS is composed of a front-end machine (Power7 Linux) and the massively parallel BG/Q machine. The front-end of Turing is the only machine which is visible and directly accessible to users. It offers the following functionalities: interactive connection, cross-compilation for BG/Q; preparation, submission and follow-up of LoadLeveler jobs.

The Turing system must be considered as an execution platform for parallel jobs launched from the front-end machine via the batch scheduler. Direct connections to compute nodes are impossible on the BG/Q. Connection to the Turing front-end is via ssh : ssh username@turing.idris.fr (followed by the user password, if you have not configured the key).

Ada :

The Ada cluster installed at IDRIS is composed of 334 IBM x3750-M4 machines (four eight-core Intel E5-4650 Sandy Bridge processors under Red Hat Linux). The front-end of Ada is the only of these machines which is visible and directly accessible to users. The front-end offers the following functionalities: interactive connection, compilation for the compute nodes of the cluster; preparation, submission and follow-up of LoadLeveler jobs. Parallel jobs must be executed from the front-end via the batch scheduler. No direct connections to compute nodes are authorised. Connection to the Ada front-end is via ssh : ssh rlab001@ada.idris.fr (followed by the user password, if you have not configured the key).

Adapp :

The pre-/post-processing cluster installed at IDRIS is composed of four IBM x3850 machines (four eight-core Intel E5-4650 Westmere processors under Red Hat Linux). The front-end Adapp is the only machine of the cluster which is visible and directly accessible to users. The front-end offers the following functionalities: interactive connection, compilation for the other nodes of the pre-/post-processing cluster; preparation, submission and follow-up of LoadLeveler jobs. Connection to the Adapp front-end is via ssh : ssh rlab001@adapp.idris.fr (followed by the user password, if you have not configured the key).

Management of the shell environment

What shells are available on the IDRIS machines?

The Bourne-Again Shell (bash) and the TC Shell (tcsh) are the two command interpreters installed on the IDRIS machines. The Bourne-Again Shell (bash) is an important evolution of the former Bourne shell (sh) and provides advanced functionalities. Therefore, using bash is highly recommended and it is the default setting on the IDRIS machines.

What environment file is executed during the launching of a login session in bash?

The environment file is .bash_profile and it must be found in your HOME. The environment variables must be put by the user into this file which is automatically executed at each interactive session. Any aliases and user-defined shell functions are put in the .bashrc file which is run at the launching of each sub-shell. To define the aliases in the interactive shell, the user must execute .bashrc in the .bash_profile.

Attention: Overwriting the PATH variable inevitably creates problems. For this reason, it is always advised to conserve the PATH which is provided by the machine. If you wish to add a research directory for the execution of local commands to be used during your future sessions, you must procede as follows in your .bash_profile file:

 export PATH=$PATH:repertoire_a_ajouter 

How to define a convivial environment in bash

The Bash shell proposes two edition modes, emacs and vi. The default mode is emacs. If you prefer the vi mode , you may choose this (or change back to the emacs mode) by using the set command:

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

Place this command in your .bash_profile environment file.

You may edit the command line by using the editing commands of the chosen editor (emacs or vi). For example, to go on the first character of the command, type: Ctrl-a if in emacs mode, or Esc-0 if in vi mode.

To edit the last command which you have launched, it is the same as going back up a line in your editor (Ctrl-P in emacs mode, Esc-k in vi mode). (See man bash for more information about the edition modes.)

You may use filename completion to avoid typing the name of the file. If the file is present in the directory, you just need to type the first letters of the name, then Esc-Esc if in emacs mode, or Esc- in vi mode.

How to change the shell

It is highly recommended to use the Bourne-Again Shell (bash) which is installed by default on the IDRIS machines. However, it is possible to use the TC Shell (tcsh). In this case, you can use the lchsh command (see man lchsh) to change to tcsh.

The login shell is obligatorily the same on Ada, Adapp, Turing and Ergon.