The Lofar Login Environment (LLE)

This page describes the standard login environment for new users on the LOFAR cluster nodes like CEP3. Existing accounts can be easily modified; see below for a manual to do this.

The Lofar Login Environment sets a few things for your account, and allows you to easily initialise often used packages and tools at login time. To this purpose we provide a few simple standardized login-scripts.

To be able to use the LLE environment you must either use a (t)csh or bash login shell. We do not support scripts for any other shells.

The CEP3 user creation system has been setup such that new accounts will have all needed files and links in $HOME in place already. So you do not have to chnage anything to work with the LLE.

To use the LLE in an existing account and $HOME dir, rename your existing .cshrc, or .profile and .bashrc, in your $HOME and follow the instructions given above.

Some of the details are presented here.

In directory /opt/cep/login are a number of default login scripts. The scripts ending with .bash are for the bash shell, the others for the (t)csh shell:

• cshrc → login settings for (t)csh environments.
• bashrc → login settings for non-interactive logins.
• profile → login settings for interactive logins.
• login → Displays welcome message; no settings.
• setpackages → script to define packages to initialize at login-time.

Users should NEVER modify these default scripts. In their $HOME these should be symlinks to the versions in /opt/cep/login. Personalization of your login is possible through other scripts like .myalias and .mysetenv (see below).

If you like to read more on the files that play a role in the bash login, here is a nice link.

Personal command aliases can be added to a file $HOME/.myalias. When this file exists, the .cshrc or .bashrc script will read this file.

Personal extensions to $PATH, personal environment variables, personal prompt setting, or overloaded existing environment variables should be done in a file $HOME/.mysetenv. If this file exists, the cshrc or bashrc script will read this file.

Many packages are available from the distribution of the Operating System. Several packages are added lateron, see this page for CEP3 packages. To activate these, environment variables like PATH, LD_LIBRARY_PATH, PYTHONPATH must be set correctly. To help you, we have installed the environment module software (see this section in the CEP3 user documentation).

To initialize the use of installed packages at login time you must create a file $HOME/.mypackages. If this file exists, it is used by the LLE script setpackages.

The file $HOME/.mypackages can look like this example:

casa
lofim

Provide only one package name per line. For packages that are build daily and that have a version available for all days of the week (LUS, LofIm), you can also specify a day of week in the .mypackages file:

lofim Tue

Apart from the systemwide module initialization files provided in directory $APS_LOCAL/modulefiles, users can add their personal modulefiles in their $HOME/modulefiles and have these run at login time. To add a new, personal, modulefile, act as follows:

• Install the package
• Create a $HOME/modulefiles/<package>/<modulefile> environment module script (e.g., adding the installation directory to your $PATH). See this manual for writing modulefiles yourself.
• Add <package> to the list of packages in file $HOME/.mypackages

To start up an X environment you have to make sure that

• The files $HOME/.xinitrc and $HOME/.xsession are removed

Determine the colordepth that you need (8, 16, 24 bit display) and type:

  startx -- :1 -depth <colordepth>

This should start your X environment at the proper colordepth. This will create an additional X Server next to the one you are already running. You can access this with Alt-F8 or Cntl-Alt-F8. The F7 variant will give you back your normal X.

Due to the large latency and largte bandwidth required for X-traffic, it is advisable to connect to the CEP systems with the NX-client on your system. See this page for more info.

If you need help, or have questions, or want to give any other comments, contact Arno Schoenmakers or Jasmin Klipic.

New module-files can be added at any time if you have a new package that should be available systemwide. Contact Arno Schoenmakers or Jasmin Klipic in this case.