More Lam MPI goodness

I forgot to mention how to create the wolf-lam account in my last post. Simply copy the line in /etc/passwd for the wolf account and change the home directory to /home/wolf/.lam and the user name to wolf-lam and then also edit /etc/shadow to include a password for lam-wolf (copy the wolf line and change the name to wolf-lam)

For RMPI to run, the shared library "/lib/libutil.so.1" has to be loaded and perhaps /usr/local/lam-7.1.2/lib/liblam.so.0 so I added:
LD_PRELOAD=/usr/local/lam-7.1.2/lib/liblam.so.0:/lib/libutil.so.1
into the switch-lammpi command

Multi MPI installation

Oh geeze what a headache, here's the important things to know:

each mpi installation is installed with the prefix /usr/local, meaning that the binarys for lam mpi are found in "/usr/local/lam-7.1.2/bin" and libraries in "/usr/local/lam-7.1.2/lib"

The default environment is altered in the system global script "/etc/bashrc" to set open mpi's binary's to be in the path and libraries in the LD_LIBRARY_PATH.

to enable lamboot to work, the PATH and LD_LIBRARY_PATH to include lam, so that it can first boot, but since our default is open-mpi this causes some problems. Our work around is to create a second account with the same uid that has a home directory that is the sub directory ~/.lam of the first account that includes a bashrc that sets LAM to be in the default environment.

Also the LAMRSH needs to be set to equal "ssh -l $USER{-wolf}" so that when lamboot issues the ssh comand it sshes in as the wolf user.

Future areas of exporlation include seeing if including lam binaries after open mpi libraries allows it to boot (then run mpi with a script that chanes the appropriate environment varibles before running the lam executable) or seeing if the ssh comand used by lamboot can be run artificaly to simulate lamboot behavior.

-William Voorhees