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 Turing front-end is the only machine which is visible and directly accessible to users. It offers the following functionalities: interactive connection, cross-compilation for BG/Q; and preparation, submission and follow-up of LoadLeveler jobs. The BG/Q must be considered as an execution platform for parallel jobs launched via the batch scheduler from the front-end machine. No direct connections to compute nodes are possible on the BG/Q. Connection to the Turing front-end is via ssh : ssh rlab001@ada.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 Ada front-end 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 via the batch scheduler from the front-end. 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 architecture installed at IDRIS is composed of four IBM x3850 machines (four eight-core Intel E5-4650 Westmere processors under Red Hat Linux). The Adapp front-end is the only of the four machines which is visible and directly accessible to users. It offers the following functionalities: interactive connection, compilation for the other nodes of the pre-/post-processing cluster; and preparation, submission and follow-up of LoadLeveler jobs. Parallel jobs must be executed via the batch scheduler from the front-end. No direct connections to compute nodes is authorised. 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 bash shell is the default setting. The Bourne-Again Shell (bash) is an important evolution of the former Bourne shell (sh) and provides advanced functionalities. Therefore, we highly recommend using bash on the IDRIS machines.

What environment files are executed during the launching of a login session in bash?

The preferred environment file is .bash_profile and it must be found in your HOME. If not, the .profile file may be used if it is in your HOME. This file is automatically executed at the login and only one time per session. The user must define the environment variables and personal programs in this file. Any aliases and user-defined shell functions should be put in the .bashrc file which is run at the launching of each non-login sub-shell.

It is preferable to use only one environment file, either .bash_profile or .profile.

Important note: Overwriting the PATH variable inevitably creates 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 procede in the following manner in your .bash_profile or .profile file:

 export PATH=$PATH: directory to add 

How to define a user-friendly environment in bash

The Bash shell proposes two edition modes, to be chosen according to your preference, available by using the set command:

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

This command should be placed in your environment file, .bash_profile or .profile.

You may then place yourself on the command line as if you were using your favourite editor. To place yourself on the first character of the command, type Ctrl-a in emacs mode (or Esc-0 in vi mode).

To re-edit the last command which you have launched, it is the same thing as going back up a line in your editor: Ctrl-P in emacs mode, Esc-k in vi mode, and so on. (See man bash for more information about the possibilities of these two modes.)

Keep in mind that you may use the filename completion function to avoid having to type the entire filename. 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- if in vi mode.

emacs : Esc-Esc,
vi : Esc-

How to change the shell

The login shell installed by default on the IDRIS machines is the Bourne Again shell (bash). If, after reading the above information, you still want to use the TC Shell (tcsh), please contact the User Support Team.

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