[aspect-devel] Error in moving temporary files during output

[Wolfgang Bangerth]

Hi Rene,

> I have a follow up question on the Input/Output issue Wolfgang had. I am
> currently doing scaling tests on a Cray XC30 up to 4000 cores and
> getting the same error messages. I am writing in a designated $WORK
> directory that is intended for data output, however there is also a fast
> local $TMPDIR directory on each compute node.
> I guess my question is: Is the Number of grouped files = 1 parameter
> always useful in case of a large parallel computation and an existent
> MPI I/O system or is this cluster specific (in that case I will just
> contact the system administrators for help)?

Timo has already answered this. I only want to add that if you get a single 
file from 4000 cores, what are you going to do with it? Do you have methods to 
actually visualize it?

This said, I thought I had implemented a fall-back where if a write to $TMPDIR 
fails, it simply writes directly to the destination directory. Only if that 
fails too do you get an error.


> Another thing I would like to mention is that this system only allows
> for static linking. With my limited knowledge I was only able to compile
> ASPECT by commenting out the option to dynamically load external
> libraries by user input. Could somebody who introduced the possibility
> to dynamically load libraries at runtime comment on the work to make
> this a switch at compile-time? I dont know much about this, otherwise I
> would search for a solution myself. In case this creates a longer
> discussion I will open up a new thread on the mailing list.

It should be easy to do, but let me try to understand the problem before I 
make changes: in order to get it to work, did you need to comment out the call 
to dlopen in main.cc because there is no dlopen function on that system? Or 
what was it that didn't work?

Best
  W.

-- 
------------------------------------------------------------------------
Wolfgang Bangerth               email:            bangerth at math.tamu.edu
                                 www: http://www.math.tamu.edu/~bangerth/