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Institute for Advanced Simulation (IAS)

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Prerequisite for using the JUDGE system is to successfully pass through the application process.

Login Procedure

Users can't login by suppling username/password credentials. Instead password free login based on SSH key exchange has been set up for the authentification process.

The public ssh key has to be generated on the workstation you are using for accessing JUDGE. The key can be generated by executing

ssh-keygen -t [dsa|rsa]

Please protect the ssh key with a non-trivial pass phrase to fulfill the FZJ security policy. (For further details on ssh key generation see FAQ: How to generate ssh keys)

The contents of the files or key must be uploaded through the WEB interface when initially applying for a userid. It will be appended to $HOME/.ssh/authorized_keys during the creation of your account on JUDGE.
Note: Make sure there is no write access for group or world on the $HOME directory, otherwise .ssh does not work.
In case your SSH key became unavailable for an existing account, please use the dispatch ssh-key upload page, to initiate the installation of a new key.
After that a typical login looks like

ssh <userid>

Login Environment


The Login Shell on each system points to system's favored shell: JUDGE -> bash
Users are not allowed to change the Login Shell, but they can switch to a personal shell within the login process. User's will find a template within the initial FZJ .bashrc in $HOME.

Home directory ($HOME)

Home directories reside on the GPFS filesystem. In order to hide the details of the home filesystem layout the full path to the home directory of each user is stored in the shell environment variable $HOME. References to files in the home directory should always be made through the $HOME environment variable. The initialization of $HOME will be performed during the login process.

Other filesystems

Other important storage locations are the scratch filesystem ($WORK), and the archive filesystems ($ARCH). The following table summarizes the information again:

VariableStorage LocationDescription
$HOMEGPFS filesystemUser's home directory
$WORKGPFS filesystemUser's storage location for fast scratch
$ARCHGPFS filesystemUser's storage location for archiving

It is highly recommended to access files always with help of these variables. The values of these variables are automatically set during login.

Programming environment ('/usr/local')

The persistent settings for the shell environment are governed by the content of .bashrc, .profile or scripts sourced from within these files. Please use these file for storing your personal settings.
The common programming environment is maintained with the concept of software modules in directory '/usr/local'. The frame work provides a set of installed libraries and application (including multiple version support) and an easy to use interface (module command) to set-up the correct shell environment.
Shell environment configuration for applications installed in the subdirectories of '/usr/local' which needs configuration extensions of common (PATH, LD_LIBRARY_PATH,...) or special environment variables are left to the users responsibility. The documentation can be found (normally) in the installation directory of the particular software package.