The ELA Server
Ela is the new CSCS frontend. It is going to completely replace bar which is planned to be switched off by the end of the first quarter of 2010. The main purpose of ela is to provide login facilities for user access. However, it can also be used as replacement of rosa's login nodes and therefore it can be used to compile your applications.
Short Machine Description
Ela is a Linux system with 2 login nodes, each node consists of 4 quad-core AMD Opteron 2.4 GHz processors giving 16 cores in total per node with 128 GB of memory.
How to connect to the interactive server
The hostname of the interactive server is ela.cscs.ch. Users worldwide can connect directly to the interactive server using the ssh(1) command. This is an example of how an ssh screen might look like:
> ssh ela.cscs.ch
===============================================================
IMPORTANT REMINDER FOR USERS of CSCS facilities
www-users.cscs.ch - help(at)cscs.ch - +41 91 610 82 10
===============================================================
CSCS next preventive maintenance is scheduled for:
>>> February 1, 2010 <<<username@ela:~$
Programming environment
Ela uses the modules framework to simplify access to various compiler suites, libraries, tools, and applications. When you log in to ela a set of base modules is loaded. By default ela is using the programming environment of Rosa. The modules currently loaded are shown by the module list command. You can load your preferred programming environment with the module load command. The names of the modules referring to the different compiler suites have names starting with PrgEnv-. For example, if you wish to load the default PGI programming environment, type this command line:
module load PrgEnv-pgi
To switch between programming environments use the module switch command.
Normally, make will execute only one command at a time, waiting for it to finish before executing the next. By using the -j (or --jobs) flag, the make command allows to compile more than 1 source file at once. Similarly, you can use the -l (or --max-load) flag to tell make to limit the number of jobs to run at once, based on the load average of the system. We recommend you to use the parallel compilation feature of the make command. As ela is shared amongst all the users, when the system is heavily loaded, you will probably want to run fewer jobs.
More informations about the modules framework and the programming environment can be found in the Compilers and Programming of Rosa.