wiki:ComputingRessources

Version 12 (modified by sommeria, 10 years ago) (diff)

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Access to the computer ressource of LEGI

Computer account

All members of LEGI, including visitors, receive a computer login and password, common to all the computers belonging to the network at LEGI. This gives access to the intranet of LEGI (in French), which contains various information, in particular information about access to the computing ressource.

You get a local e-mail address with your account. This provides you access to general information, for instance seminar announcements or any event.

To enable cable connection of your own laptop to internet and the local network, please contact the computer support service of LEGI. In most rooms we have also wifi access through Wifi Eduroam and Wifi-Campus but you need to be registered on these systems.

To connect to your e-mails, you can use the webmail Access to webmail, or for better access configure Icedove-Thunderbird. The web server of LEGI is servmail.legi.grenoble-inp.fr.

Common computing ressource are reached through the server 'servcalcul3' under Linux system ( a few useful Linux commands). To reach this server from a Linux machine at LEGI, use the command ssh -CX servcalcul3 (the option '-CX' provides a graphic terminal).

For any request about computers, please send an e-mail to [support
@legi.grenoble-inp.fr] .

Access to bibliography

Once connected to your computer at LEGI, you can access online to a wide list of journals through the gate 'G@el': http://sicd1.ujf-grenoble.fr/-Periodiques-electroniques. Then an indication 'University Joseph Fourier' indicates that you are allowed to download the pdf of the articles. Note that this does not include access to old issues of J. Fluid Mech, prior to 1997. For that you need to connect directly without going to Gael, and the logo 'LEGI' should appear.

Remote access to the computers at LEGI

You can use the terminal [x2Go -> http://wiki.x2go.org].

X2Go replaces NX client as the new versions of this software do not work on our system. You need to use the host 'legilnx02.legi.grenoble-inp.fr', then type ssh -CX servcalcul3 to access the computing server.

Obsolete: NX client can be directly downloaded from http://www.nomachine.com/download.php.

After installation you need to configure the connection settings:

  • host: servcalcul3.legi.grenoble-inp.fr
  • key: select the option Use an alternate Server key’ and upload a key ('certificat') text file.
  • 'Enable SSL for all traffic' (default), do not 'connect through http proxy'
  • different user interfaces can be chosen. The interface 'KDE' is fairly similar to Windows system.
  • graphical options: for a fast response select
    • disable DirectDraw
    • disable deferred screen update
    • disable ZLIB stream compression
  • keyboard: pour un clavier francais, utiliser le menu 'Advanced/Keyboard/French(Alternative)' ET si vous avez toujours des problemes sous KDE :
    • tapez la commande setxkbmap fr
    • dans le menu "Control Center" puis "Regional & Accessibility" puis Keyboard Layout choisissez Model 105 Keys et layout France, vous devriez avoir un petit drapeau dans la barre de menu en bas a droite pour selectionner votre clavier francais.

Data transfer

Data transfer from/to outside cannot be done by NXclient (except as attached files using mail). For that you need scp procedure, using par example filezilla. Configuration of filezilla:

  • host: servcalcul3.legi.grenoble-inp.fr
  • type of server : SFTP
  • account : normal
  • user name, etc

Data organisation

  • Connection to servcalcul3 brings you to your home directory named /home/users/'login name'. Your home is not visible by other users. It is saved dayly (do not turn off your computer during night). Its disk space is limited by default but you can ask more, although it is not designed for massive data storage.
  • Large data sets for specific projects are stored in /fsnet/project/. For the Coriolis facility, data are stored in /.fsnet/project/coriolis with sub-folders indicating the year of project completion.
  • For informal sharing of documents (within the team 'MEIGE'), you can use the folder /.fsnet/team/team-meige/pub .
  • Documents about the Coriolis platform are available in /.fsnet/data/team-meige/coriolis-doc.

More information is provided in HowTo/Data and HowTo/Backup.

Matlab

Open matlab by typing 'matlab' from a terminal, or 'matlab &' to keep the terminal active for new commands. Choose as 'Current Folder' the folder which contains your processing functions. An alternative option is to declare paths to your functions, using the matlab function 'addpath' (be cause of the system installation the set of paths are not saved for next opening of matlab).

To avoid overload of the server, it is advised to work on a cluster node instead of servcalcul3. This is done by typing oarsub -I on a terminal prior to opening matlab. The session is limited by default to 2 hours, but this duration can be increased, for instance to 10 hours, with the option 'oarsub -I -l walltime=10:0:0' . More advanced computing distribution on the cluster can be done with the oar system.

To reproduce the keyboard shortcuts of Windows OS, set ‘file Preferences’, Keyboard , Shortcuts then select “WINDOWS DEFAUTLS SET.

Further information on matlab.

Particle imaging velocimetry and related image analysis can be performed by the matlab package uvmat. This also provides general tools for reading netcdf files, for compiling matlab programs and distribute them on the cluster.