Firefly and PC GAMESS-related discussion club

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Jiri Wiesner
wiesner@chemi.muni.cz

I would like to run Firefly in a machine with 8 processors, each with 4 cores under 64bit/32bit emul. Debian GNU/Linux 5.0.3, kernel 2.6.30, libc 2.7. I'm using Open MPI version of Firefly, as Open MPI it installed on our cluster in version 1.2.9. Our 32 CPU machine has only one RAID device, where I can store integrals during MP4 integral transformation.

And here is the obstacle: When I use 8 parallel processes through OMPI (mpirun -np 8), I'm running out of the disk space soon. When I use MKLNP=8 flag for SMP, the first HF computation and some other part are running on 1 CPU (slow on larger systems with large basis sets). I chose to run 2 OMPI processes and use MKLNP=4. In this case the space for the DASORT and MOINTS files is twice as large, but the machine can manage that.

My question is: Is there any better way how to run on one node on as many CPUs as possible and use as little disk space as possible? Is it possible to force MPI processes to use a single set of integral files?

Thank you for your answers.
Jiri