Troubleshooting

This chapter provides a description of a problem that might occur when you are running Compaq MPI and how to solve it; and of potential problems that may occur when Compaq MPI is terminating. It also provides contact information in case you wish to send comments or suggestions. The chapter consists of the following sections:

5.1 Problem Solving

Follow these steps if this message is displayed when you are running dmpirun:

: % dmpirun -np 2 cpi Permission denied:

Ensure the .rhosts file in your home directory is set up correctly.
To change the protection to user read/write only, enter the following command:

chmod og-rwx .rhosts

For security reasons, only the owner of the .rhosts file should have read/write access.
Add one line to the .rhosts file for each host you want to use, for example:

host username

For example, if your username is doe and you wish to use machines a.our.org and b.our.org, your .rhosts file should contain:

a.our.org doe b.our.org doe

5.2 Potential Problems when Terminating

If your program does not terminate cleanly, IPC resource may not be freed. Compaq MPI will attempt to clean up these resources on all hosts if the program is aborted using Ctrl/C. However, if the Compaq MPI processes on a host exit normally, but without calling MPI_FINALIZE, then Compaq MPI will not be aware of a problem and will not attempt to clean up.
When using some of the debuggers, dmpirun may write a temporary file which may not be deleted on termination.

The command mpiclean can be used to tidy up after abnormal terminations. This tidies up resources, IPC and temporary files on the local host only.

Note: The command mpiclean frees all IPC resources currently in use by the user, including the resources used by other programs started by this user.

5.3 Contact Information

Please send your comments and suggestions regarding the software or the manual to

: mpi@ilo.dec.com

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