[mpich-discuss] mpdcheck fails after logout

[Dorian Krause]

Richard Katz wrote:
> Hello,
>
> I am trying to run a sequence of MPI jobs from a shell script and 
> encountering this problem:
>
> after having launched the shell script in the background, if I log out 
> of the machine, the script still executes but I get:
>
> mpiexec failed: gethostbyname_ex failed for darcy.earth.ox.ac.uk
>
> for each MPI job in the script. As a test, I used the following script:
>
> #!/bin/bash
> mpdcheck -v > test_script.out
> mpiexec -np 2 ./myProg >> test_script.out < /dev/null
> mpdcheck -v >> test_script.out
> mpiexec -np 2 ./myProg >> test_script.out < /dev/null
>
> and ran it in the background. The first mpdcheck returned 
> successfully. The first run of myProg was also successful. At some 
> time during the first execution of myProg I logged out of the machine 
> and the subsequent mpdcheck and mpicheck failed. mpdcheck -v returned:
>
> obtaining hostname via gethostname and getfqdn
> gethostname gives darcy.earth.ox.ac.uk
> getfqdn gives darcy.earth.ox.ac.uk
> checking out unqualified hostname; make sure is not "localhost", etc.
> checking out qualified hostname; make sure is not "localhost", etc.
> obtain IP addrs via qualified and unqualified hostnames; make sure 
> other than 1
> 27.0.0.1
> *** gethostbyname_ex failed for this host darcy.earth.ox.ac.uk
> *** gethostbyname_ex failed for host darcy.earth.ox.ac.uk
> checking that IP addrs resolve to same host
> now do some gethostbyaddr and gethostbyname_ex for machines in hosts file
>
> If I run the script but remain logged in to the machine, there is no 
> problem.
>
> How can I fix this so that I can log out and not cause 
> gethostbyname_ex to fail?
>
> Many thanks,
> Rich
>
Hi,

Use screen or (probably easier) nohup whe starting mpd.

Dorian