Reply-to: gamsworld@googlegroups.com
Does this happen with a specific solver? Which one?
Can the problem be reproduced by solving trnsport (from the model library) instead of your own model?
–Paul
On Sat, Mar 19, 2011 at 9:27 AM, Tavallali wrote:
AndyC
I am using Windows XP 64bits…
Regards
On Thu, Mar 17, 2011 at 2:34 AM, AC wrote:
A response in case GAMS is reading this thread
Does the message pop up every time or only occasionally?
Occasionally. The same identical model can be run multiple times and
it randomly happens
\
You may want to
create a working directory (e.g d:\temp) and try to run the model there.
Tried that, no change.
\
Another option could be that a virus scanner is interfering.
We have categorically ruled out the problem being from a virus scanner
on our system.
\
- Keep all files in memory instead of writing them to disk
That’s a nice idea. It wont help us with one of our models however
as the license is not for a solver with incore ability, but it may
help with our cplex model.
Mohammad, what OS are you using??
Regards
AndyC
On Mar 16, 9:17 pm, Tavallali wrote:
Dear AndyC
Thank you for your response. I am forwarding GAMS reply to my inquiry for
your reference:
Dear Mohammad,
Thank you for contacting GAMS Support.
Does the message pop up every time or only occasionally? You may want to
create a working directory (e.g d:\temp) and try to run the model there.
Another option could be that a virus scanner is interfering. By default GAMS
does quite a few file operations during its runs and we have seen problems
aggressive virus scanners, which do not allow to access .scr files. There
are a few things you can do:
-
Instruct your virus scanner to exclude your GAMS working directory. (this
will work with any the GAMS version).
-
Instruct GAMS to use another file extension than scr for scratch files:
Starting with distribution 22.9 the default file extension of intermediate
files located in the 225? directories is .dat. The scratch extension is a
parameter that can be changed with the GAMS option ScrExt, e.g. gams
trnsport scrext=tmp. Within GAMS code you get the scratch extension using
%gams.scrext%Code Text.
-
Keep all files in memory instead of writing them to disk: No large model
scratch files need to be written to disk which can save time if you solve
many models in your GAMS program. This in-core execution is activated by
setting .solvelink=5; before the solve statement and by using
cplexd (or any other in-core solver version) instead of cplex as your lp
solver (just add the line option lp=cplexd to your model). Please note that
this increases the amount of RAM required by your model and that CPLEX can
not handle QCP models. Please note that currently only selected solvers are
supporting in core operation.
Hope this helps.
Best, Franz Nelissen
Regards
On Wed, Mar 16, 2011 at 6:11 AM, AC wrote:
Hi
Im not offering you any useful info really, other than to say that we
have also encountered exactly this issue too. Perhaps by describing
your environment (operating system, version of gams etc) we can get
some helpful info to GAMS to see if they can unravel the problem (if
it is indeed a GAMS problem)
We encountered exactly this problem ONLY when running on Windows
Vista.
Other systems running XP, same version of gams installed, same model
files etc do NOT give us this problem.
They appeared to happen completely randomly. Sometimes the model ran
fine, othertimes the error was raised.
Changing to an admin login helped reduce BUT NOT ELIMINATE the issue.
I know little about Vista, but understand it has tighter security, so
it could be something around file permissions and rights etc, maybe
those take longer to negotiate under Vista ?? (disclaimer: that’s a
wildly uninformed guess from someone with zero computer knowledge)
The issue is so regular we are in the process of upgrading to Window7
for the sole purpose of trying to make this problem go away, as the
model is just too unreliable with this problem.
GAMS - HTH. Let me know if there is any other info you want. As I
said we are upgrading to windows 7 as we speak, so I wont be able to
give you “vista” info anymore.
Regards
AndyC
On Mar 15, 4:25 am, Tavallali wrote:
Dear All
I am running a series of GAMS file. It stops at a point and generates the
following error :
*** Gams Exit Msg = Invalid argument for file: D:\225a\gamssolu.dat
Cannot delete file: 225a\gamssolu.dat
Cannot delete file: 225a\gamsstat.dat
Cannot delete directory: 225a
May I ask if you can comment why that happens? And what the solution is?
Best Regards
–
Ù…Øمد صادق تولّلی
Mohammad Sadegh Tavallali
tavallali.msad...@gmail.com
–
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–
Ù…Øمد صادق تولّلی
Mohammad Sadegh Tavallali
tavallali.msad…@gmail.com- Hide quoted text -
Ù…Øمد صادق تولّلی
Mohammad Sadegh Tavallali
tavallali.msadegh@gmail.com
Paul van der Eijk
GAMS Development Corporation
Tel : (202) 342-0180 Fax : (202) 342-0181
Email: pvandereijk@gams.com
Web : http://www.gams.com
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