4.3.1 PVM hosts file

4.3 PVM

PVM or parallel virtual machine is a freely available library for running processes on more than one processor on one or more machines. EON can take advantage of PVM to distribute jobs over multiple processors. To do this PVM must be installed on all the machines EON will be distributed over. The PVM source is freely available from

http://www.csm.ornl.gov/pvm/pvm_home.html

however many Linux distributions, and some Unix versions, include PVM by default. EON is built with the current PVM version 3.4.5, but should also work with PVM version 3.4.4. EON does not support PVM under Windows.

To use EON with PVM you must do one of the following.

Place a link or copy of the ``eon'' executable in $PVM_ROOT/bin/$PVM_ARCH
Define the enviroment variable PVM_PATH, which names the directory where the ``eon'' executable resides.

The enviroment variables PVM_ROOT and PVM_ARCH should be defined globablly as part of the PVM installation. PVM_PATH is generally a user-defined enviroment variable, and must defined for all shells (i.e., you can't just define it in the shell you're launching EON in).

NOTE : There is no specific slave executable. The executable distributed for this program serves as both a master and slave PVM program as well as a single processor version.

4.3.1 PVM hosts file

After PVM and EON are installed, each EON job run via PVM must be supplied a file (via -pvmconf) that describes the hosts and number of CPU's to use. Each line in this file includes the word ``host'' followed by the hostname of the slave followed by the number of CPU's to use on that slave.

To use 10 slaves on a linux cluster (where nodes are named ``linux1'', ``linux2'', etc.)

host linux1 2
host linux2 2
host linux3 2
host linux4 2
host linux5 2

To use 32 CPU's on a single-image system like an SGI Altix, a single line can be used:

host altix 32