I’m using OpenMPI on an Xserve cluster running OS X Server 10.4.8. The user directories exist on an XserveRAID connected to the master node via fibre channel.  So, on the master node the full pathname for the user directories is /Volumes/RAID1/users1.  The compute nodes of the cluster automount the user directories via NFS, so the full path to the user directories appears on the nodes as /xhome/users1.  I created a hostfile list of all the compute nodes on the cluster, not including the master node.  When I attempt to run a program in my home directory matt from the master node with

mpirun –hostfile nodes –np 4 program

it fails because it cannot find program.  If I add the –wdir option and specify the directory as /xhome/users1/matt, everything is fine.

My question is this, how does OpenMPI determine your working directory, and is there a way to fix this without the –wdir option?  For example, if you look at the PWD environment variable, it is always /xhome/users1/matt, even on the master.  If you use the pwd command, however, you get different the two different results on the master and the nodes.

Thanks.

Matt

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Matthew Grismer