[molpro-user] parallel molpro behavior

[Sigismondo Boschi]

Hi,

I am running for the very first times molpro in parallel on an IBM 
regatta (p690) system with colony switch.

I have used Global Arrays 3.3.1 (GA, TARGET=LAPI64), and it seems to run 
fine.

However now I want to get as much as possibile from it and I have many 
obscure points.

The typical target systems of our users are CCSD(T) optimnization.


Running one of them, I would like to use as much as possibile the memory 
for integrals, and then, if not possibile, the disk, that is a shared 
GPFS filesystem: there is no benefit in concurrent accesses to it, and 
it became the bottleneck for the code.

With typical options I have found that the task don't use much memory, 
nor standard neither in GA.

Running on 16 cpus, At the very beginning of the output I found:


**********
ARMCI configured for 2 cluster nodes

  MPP nodes  nproc
  sp154        8
  sp152        8
  ga_uses_ma=false, calling ma_init with nominal heap. Any -G option 
will be ignored.

  Primary working directories:    /scratch_ssa/abc0
  Secondary working directories:  /scratch_ssa/abc0

  blaslib=default

  MPP tuning parameters: Latency=    84 Microseconds,   Broadcast speed= 
  233 MB/sec
  default implementation of scratch files=ga
**********

Only if I use one task (or maybe, one node) I can find ga_uses_ma=true
on the other side the statement: "default implementation of scratch 
files=ga" would let me think that they are "in-memory files"... however 
what happend at run-time does not correspond to it:

In fact I observe a lot of I/O, and the used memory is about 200 MB (of 
2GB) for each task.

After the CCSD I get:
  DISK USED  *         9.10 GB
  GA USED    *       120.58 MB (max)        .00 MB (current)

And actually I set in the beginning:
  memory,200,M

(that is not the GA memory, but the -G option is ignored... I do not 
understand why).


Can anybody of you explain some of these facts, and give some suggestion 
for parallel runs?

For istance I tried also direct calculations, but:
1. it was very slow
2. it terminates with the error:

******
FILE 5 RECORD    1380 OFFSET=          0. NOT FOUND

  Records on file 5

  IREC   NAME  TYPE        OFFSET    LENGTH   IMPLEMENTATION   EXT 
PREV   PARENT  MPP_STATE
    1    4000               4096.    21301.         df          0      0 
      0      1
    2    4001              25397.   166404.         df          0      0 
      0      1
    3    4002             191801.    10725.         df          0      0 
      0      0
    4    4003             202526.   178782.         df          0      0 
      0      1
    5   35020             381308.    10496.         df          0      0 
      0      1
    6    3600             391804.      273.         df          0      0 
      0      1
    7    3601             392077.      273.         df          0      0 
      0      1
    8   35000             392350.       10.         df          0      0 
      0      1
    9   35001             392360.       10.         df          0      0 
      0      1
   10   35010             392370.      320.         df          0      0 
      0      1
   11   35011             392690.      320.         df          0      0 
      0      1
   12    7005             393010.   314964.         df          0      0 
      0      1
   13    8005             707974.   314964.         df          0      0 
      0      1
   14    9101            1022938.  9567696.         df          0      0 
      0      0
   15    9103           10590634.  9567696.         df          0      0 
      0      0

  ? Error
  ? Record not found
  ? The problem occurs in readm

  ERROR EXIT
  CURRENT STACK:      CIPRO  MAIN
*******

Many Thanks for any help

   Regards


     Sigismondo Boschi




-- 
Sigismondo Boschi, Ph.D.               tel: +39 051 6171559
CINECA (High Performance Systems)      fax: +39 051 6137273 - 6132198
via Magnanelli, 6/3                    http://instm.cineca.it
40033 Casalecchio di Reno (BO)-ITALY   http://www.cineca.it