Hi all: I'm trying to set up a cluster for a group of users with very different needs. So far, it looks like I need gcc, pgi, and intel to work with openmpi and mpich, with each user able to control what combination they get. This is turning out to be much more difficult than I expected.
Someone has pointed me to enviornment-modules ("Modules"), which looks like it will be a critical part of the solution. I even noticed that the provided openmpi.spec file has some direct support for modules, which makes me quite happy! However, I still have many questions about how to set things up. First, I get the impression that openmpi will need to be compiled with each compiler that will use it. If this is true, I'm not quite sure how to go about it. I could install in different directories for the user commands, but what about the libraries? I don't think I have a feesable way of selecting which library to use on the fly on the entire cluster for each user, so it seems like it would be better to have all the libraries available. In addition, I will need RPMs to deploy efficiently on the cluster. I suspect I can change the versioning info and build with each compiler, but at this point, I don't even know how to reliably select what compiler rpmbuild will use (I've only succeeded in using gcc). Finally, using modules, how do I set it up so that if a user changes compilers, but stays with openmpi, it will load the correct openmpi paths? I know I can set up the openmpi module file to load after the compiler module and based on that select different paths based on the currently-loaded compiler module. If the user changes the compiler module, will that cause the mpi module to also be reloaded so the new settings will be loaded? Or do I need this at all? Thanks for all your help! --Jim