Guide to Colosse - bregord/emcee-on-calcul-quebec GitHub Wiki

Colosse is Laval University's resident Supercomputer.

##Running Jobs ###Queues Available

Queues on Colosse are chosen automatically. It is not necessary to specify which one you wish to use.

###Cores Per Node All nodes have 8 cores, with 936 nodes of them having 24GB of memory.

###Requesting nodes with 48GB There are 24 nodes with 48GB of memory available to them. To request nodes with 48GB simply add '-l feature="48g"' to your qsub command when submitting your submission script

###Job Submission

Colosse automatically divides memory amongst all the processes on its node. So one 24GB node with 8 processes gives each process 3GB of memory.

Giving each process more memory is a two step process. First, choose a number of nodes and a number of processes such that the number of nodes evenly divides the number of processes

Then, use the mpiexec command with the -npernode flag to specify the number of processes per node you want. For example, the following will run 4 processes per node:

 #PBS -l nodes=2:ppn=8
 mpiexec -npernode 4 /path/to/my/mpi_program

###More Information More information about Colosse, its specs, and usage policies can be found on the Calcul Quebec wiki here

###Brendan's Note: It is important to note that I couldn't actually get emcee to run on Colosse due to problems with trying to install mpi4py with the the python2.7 modules colosse has made availabe.