HP-MPI User's Guide (11th Edition)

Frequently asked questions
Windows specific
Appendix D 309
ANSWER: The automatic job submittal will set the current working
directory for the job to the current directory. (Equivalent to using -e
MPI_WORKDIR=<path>.) Because the remote compute nodes cannot access
the local disks, they need a UNC path for the current directory.
HP-MPI can convert the local drive to a UNC path if the local drive is a
mapped network drive. So running from the mapped drive instead of the
local disk allows HP-MPI to set a working directory to a visible UNC
path on remote nodes.
QUESTION: I run a batch script before my MPI job, but it fails. Why?
ANSWER: Batch files run in a command window. When the batch file
starts, Windows will first start a command window and try to set the
directory to the 'working directory' indicated by the job. This is usually a
UNC path so all remote nodes can see this directory. But command
windows cannot change directory to a UNC path.
One option is to use VBScript instead of .bat files for scripting tasks.