[Gmsh] Error due to many volumes

[Christophe Geuzaine]

Romain Quey wrote:
> Christophe - Yes, it only happens with Netgen.
> 

OK. We've uploaded Gmsh 2.2.1, which should fix the problem. Can you 
give it a try?

Thanks,
Christophe


> Quoting Christophe Geuzaine <cgeuzaine at ulg.ac.be>:
> 
>> Werner, Romain - I think I might understand where the problem comes  
>> from: does it only happen with the Netgen algorithm?
>>
>>
>>
>> magpar wrote:
>>> Dear Romain,
>>> Dear Gmsh developers and users,
>>>
>>> I can confirm Romain's problem and his solution:
>>>
>>> http://www.geuz.org/pipermail/gmsh/2008/003316.html
>>>
>>>>> Romain Quey wrote:
>>>>>> Dear Gmsh developers, dear all,
>>>>>>
>>>>>> Using gmsh 2.2.0 on Linux, I'm having the following error:
>>>>>>
>>>>>> $ gmsh -3 n1100-id1.geo
>>>>>> Info    : Parsing file 'n1100-id1.geo'
>>>>>> Error   : [on processor 0] Unable to open file 'n1100-id1.msh'
>>>>>>
>>>>>> My geo file contains many 'Volume' definitions (1100) -- see the  
>>>>>>  attached example.
>>> [...]
>>>
>>>> You are right, the bug does not occur here, but when writing the mesh.
>>>>
>>>> However, I think the reason for the bug is really this one: when
>>>> increasing the max number of openable files per process on my system
>>>> (from 1024 to 1000000), I can successfully mesh the file.  I think that
>>>> if you run 'ulimit -n 1024' on your system, gmsh will crash too.
>>> I observed similar problems with models with many volumes a while  
>>> ago and reported them on the gmsh mailing list:
>>>
>>> http://www.geuz.org/pipermail/gmsh/2007/002946.html
>>> http://www.geuz.org/pipermail/gmsh/2007/002831.html
>>> http://www.geuz.org/pipermail/gmsh/2007/002826.html
>>> http://www.geuz.org/pipermail/gmsh/2007/002947.html
>>> http://www.geuz.org/search/search-geuz.cgi?q=magpar&ul=%2Fpipermail%2Fgmsh%2F&ps=10
>>>
>>> Based on Romain's observation I tested his solution to increase the  
>>> resources (max. number of open files) on the shell and I can  
>>> confirm that this fixes my problems, too.
>>>
>>> Here is an example (from one of my earlier posts) which exhibits  
>>> the problem (mesh generation is successful, but the msh file cannot  
>>> be saved):
>>> http://www.geuz.org/pipermail/gmsh/attachments/20071214/5a438bd7/attachment-0005.gz
>>>
>>> To make this increase in the resources permanent one has to modify  
>>> the limits in /etc/security/limits.conf by adding or modifying the  
>>> line
>>>
>>> *                hard    nofile          10000
>>>
>>> After that it is necessary to login on a new shell or even reboot  
>>> the machine because new processes inherit this setting from the  
>>> process/shell which launches it.
>>>
>>> So, finally the question is why gmsh keeps so many files open (one  
>>> for each volume!?) and how this could be fixed.
>>>
>>> Thanks for the useful discussion and help on this mailing list  
>>> which fixed my problem, too!
>>>
>>> Werner
>>>
>>
>> -- 
>> Prof. Christophe Geuzaine
>> University of Liege, Electrical Engineering and Computer Science
>> http://www.montefiore.ulg.ac.be/~geuzaine
>>
> 
> 
> 


-- 
Prof. Christophe Geuzaine
University of Liege, Electrical Engineering and Computer Science
http://www.montefiore.ulg.ac.be/~geuzaine