Subject: summary of large rwf spliting

From: "benny" <[email-masked]>
Date: Wed, 28 Feb 2001 22:19:17 +0800

Dear CCL Members:
  
According your advice, I have solved the large rwf spling problem.
ere is my adding line.

%RWF=f1,2000MB,f2,2000MB,f3,2000MB

or

%RWF=f1,240MW,f2,240MW,f3,240MW

the default path is the current directory.

You may give the path, such as

%RWF=/home/lboc/tmp1/f1,2000MB,/home/lboc/tmp2/f2,2000MB

Here is the summary. thanks to everyone.

THE original problem is:

    I use Gaussian A.7 to do MP2 frequency calculation.My workstation's
configuration is 30G hard disk and 780M memory. However,when I calculate
a system with 7 heavy atoms using MP2/6-31+g**, The calcualtion will stop
with the following message: 
 
Erroneous write during file extend. write 114687 instead of 4096
Probably out of disk space.

I have split the scratch file as the following:

      %rwf=f1,2GB,f2,2GB

However,the calculation still stop after the first file(f1) exceed 2.1G,while
f2 do not contain any data. Does anyone have the similar experience and how
to deal with the problem?
Thanks a lot!
Yours

-----------------------------
REPLY from Matthias is:
in former versions of Gaussian, the memory limit in the %rwf line
_must_ be in words. I'm not sure about G98 Rel.A7.
I also used in all cases slightly less than 2 GB for each file,
as example:
%RWF=/scratch/f1.rwf,200000000,/scratch/f2.rwf,230000000,/scratch/f3.rwf,-1

Maybe this helps.

Matthias

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REPLY from Paul is:
I had this pb some times. It seemed to me that it was a file system
limitation : they must not
exceed 2GB.... but with G98, I discovered that most of the times, I had to put
the limit well below, around
1.5GB or 1.6GB.

  Hope this helps,
Paul.

Fleurat-Lessard Paul                        | [email-masked]   
Laboratoire de Physico Chimie Moleculaire,  | Phone: (33)(0)5 56 84 63 09
Universite Bordeaux I, 33400 Talence, FRANCE| Fax : (33)(0) 5 56 84 66 45

------------------------------
REPLY from Roy is:
You may need to add a decimal point to the numbers. I had problems with 2
and 2.0GB rwf files. Try makin the rwf files 1.8GB.

Roy Jensen

-------------------------
REPLY from Tapas is:
Check the limit of filesize using command "limit"  (in AIX), ulimit (TrueUnix).
Change it to unlimited.

Tapas Kar, Ph. D
Department of Chemistry & Biochemistry
Utah State University
Logan, UT 84322-0300

Tel: 435-797-7230
Fax: 435-797-3390
Email: [email-masked]
       [email-masked]

---------------------------
REPLY from Cust. is:
While formally files up to 2GB can be used there is overhead which is
makes some of this unavailable.  I find that 240MW is safe for all calculations
so

%rwf=f1,240mw,f2,240mw
#  ... MaxDisk=480mw

should get you past the 2GB limit.

  Note that MP2 frequencies cannot restrict things to the MaxDisk limit
but you will get a note on the smallest disk required. I suspect for this
case that two files will be sufficient but you should consider defining
more to be on the safe side since you have enough.  The maximum is 8 files
for about 16GB and if you shorten the file names to a single character
you will be able to fit it all on one 80 character line.

-----------------
REPLY from Prof.Curt is

Have you tried the Gaussian route card option MP2=semidirect?  I think
you need to reduce your scratch / rwf usage to get around these
limitations.  You may also have run up against an old OS limitation on
file size.

Curt Breneman
RPI Chemistry

---------------------
REPLY from Pedro is
Hi
try SCF=Direct Maxdisk=4200Mb or the maximum available

hope it helps

 Pedro Salvador Sedano             |
 Ph.D. Student                     | I'll stare the sundown
 Institut de Quimica Computacional |  until my eyes go blind...
 Universitat de Girona             |  I won't change direction
 Campus Montilivi 17071            |   and I won't change my mind.
 Girona  Spain                     |
 e-mail: [email-masked]       |
 WWW: http://stark.udg.es/~perico  |
 Telf: +34 972 418358              |

---------------------
REPLY from Thomas is
splitting th rw-file is probably without any success unless you have
some restrictions concerning the maximum filesize at your system. First
you should try the option: MP2(VeryStingy) and have a look if using
MP2(FullDirect) works. Then there are some other possible problems. See
if the MaxDisk-option in the Default.Route file is set. If you do not
find a Default.Route file then there are no MaxDisk restrictions. But as
far as my experience goes to allocate 4GB for the rw-file is very often
insufficient. If you can try %rwf=f1,20GB. Last but not least you should
see what's the size of your f1 and f2 at the error termination of your
job. If both are 2GB then you need to allocate more disk space otherwise
there is another problem.
Hope could help you

--------------
REPLY from Borislav is
I think you should try with %rwf=f1,240MW,f2,240MW. 

                                    Boris

===========================================================================

  Boris Kovacevic                       Phone: (385) (1) 4561-117
  Quantum chemistry group               Fax:   (385) (1) 4561-118
  Institut Rudjer Boskovic              e-mail: [email-masked]
  Bijenicka 54, 10000 Zagreb            http:
  Croatia

----------------
REPLY from Thomas is
sorry I did not read the last sentences of your mail. I know this
problem. First try
%rwf=f1,2GB,f2,2GB,
The last comma is important! If that doesn't work try

%rwf=f1,230MW,f2,2GB,

But why do you split your rw-file and why don't you allocate
%rwf=f1,2GB  ???
Please tell me if you have any success.

Greetings
Thomas

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