Chapter 7. Configure gm-mpich

In order to use gm-mpich, every MPICH user must have a gm configuration file. The default file is $HOME/.gmpi/conf.

The configuration file must contain the following information:

number_of_mpi_process
node port [board]
node port [board]
...

The fields are as follows:

Comments (those lines that begin with #) and blank lines are ignored.

The following example, in the case with multiple boards on node node02:

# The first non-commented line must contain the number of
# nodes in the cluster:
3
# The following should contain the hostname and port for
# each interface:
red.sgi.com 2
node02.sgi.com 2
node02.sgi.com 2 1

When installing the gm-mpich package, the installace utility creates a file named /etc/ace/gmpi.conf on every node. The installace utility assumes that every node is using port 2. Users can copy this file to $HOME/.gmpi/conf on every node; this is done automatically for the root user. To use a different file location, a user can set the GMPICONF environment variable to the file as follows:

# export GMPICONF=/etc/ace/gmpi.conf

This file must be accessible on all nodes. When using PBS, this environment variable must be set in the PBS request's environment.