PC GAMESS/Firefly-related discussion club

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Alex Granovsky
gran@classic.chem.msu.su

>Btw, sometimes I get the error:

>p4_error: semget failed for setnum: 0

>and the execution freeze.

>Any hint?

this (well-known) problem is specific to mpich binaries.
More specifically, mpich is not always capable to perform
complete cleanup of sysv semaphores and shared memory segments
it uses, e.g. when the PC GAMESS/Firefly binaries were forcibly
terminated by user, killed by queue system, and so on.

The problem is that sysv ipc objects are not removed
automatically under Unix/Linux, even if they are not referenced anymore.

The solution is to use cleanipcs script of mpich distribution,
or some equivalent. The ipcrm utility is capable to remove sysv ipc objects.

Hope this helps.

Regards,
Alex