Permission Denied


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Question:
When I use mpirun, I get the message Permission denied, connection reset by peer, or poll: protocol failure in circuit setup when trying to run mpich.
Answer:
If you see something like this 

    % mpirun -np 2 cpi  
    Permission denied.
(or connection reset by peer or poll: protocol failure in circuit setup) when using the ch_p4 device, it probably means that you do not have permission to use rsh to start processes. The script tstmachines can be used to test this. For example, if the architecture type (the -arch argument to configure) is sun4, then try 
    tstmachines sun4
If this fails, then you may need a .rhosts or /etc/hosts.equiv file (you may need to see your system administrator) or you may need to use the p4 server. Another possible problem is the choice of the remote shell program; some systems have several. Check with your systems administrator about which version of rsh or remsh you should be using.
If your system allows a .rhosts file, do the following:
* Create a file .rhosts in your home directory

* Change the protection on it to user read/write only: chmod og-rwx .rhosts.

* Add one line to the .rhosts file for each processor that you want to use. The format is 


host username
For example, if your username is doe and you want to user machines a.our.org and b.our.org, your .rhosts file should contain 


a.our.org doe 
b.our.org doe
Note the use of fully qualified host names (some systems require this).
On networks where the use of .rhosts files is not allowed, (such as the one in MCS at Argonne), you should use the p4 server to run on machines that are not trusted by the machine that you are initiating the job from.
Finally, you may need to use a non-standard rsh command within mpich. mpich must be reconfigured with -rsh=command_name, and perhaps also with -rshnol if the remote shell command does not support the -l argument. Systems using Kerberos and/or AFS may need this.


Up: Frequently Asked Questions Next: Notes on getting MPICH running Under Linux Previous: Using MPICH