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-   -   Graphic/plotted monitors causing Fluent 12.0 to crash (http://www.cfd-online.com/Forums/fluent/75488-graphic-plotted-monitors-causing-fluent-12-0-crash.html)

Autumn April 27, 2010 10:28

Graphic/plotted monitors causing Fluent 12.0 to crash
 
When I attempt to monitor and plot a solution variable in Fluent 12.0, Fluent often crashes. This does not always happen, sometimes the monitors are plotted for x amount of time, but as the simulation runs Fluent will eventually crash. Sometimes I get the following error:

No error handler
Cortex Fatal Signal (SEGMENTATION VIOLATION)

and sometimes Fluent 12.0 will crash and quit without any error message or warning. I believe this problem is a graphics related problem. When I save the monitor data to a file without plotting the values during the calculation I do not observe any problems/crashes.

I am hoping this is a bug that is fixed in 12.1. I am curious if anyone else has observed this behavior? I am running Fluent 12.0 on a cluster, 64 bit, Linux.

leonardo.morita April 28, 2010 08:26

One common reason for segmentation violation is lack of memory. Have you tried to check the amount of RAM used by Fluent when running your case?

Allan Walsh April 29, 2010 13:12

I am not too familiar with running Fluent on Linux as we have always used Windows, but we had problems that seemed similar. When running Fluent 12.0 and using separate windows to monitor the solution, it would crash at least once a day, if not several times. We had two systems running Fluent, and both did the same. Ansys told us it was a problem with the setup of both of our systems???
Now that we have been using 12.1.4, it only crashes once in awhile (maybe once a week). But, we have changed to using embedded windows instead of separate windows for monitors and plotting outuput, which I think helps.
Does Fluent 12 on Linux include embedded windows? Ansys would never explain why their new approach is to use embedded windows, but I assumed it was a marketing strategy to get people to use their Workbench and sell more software.

Autumn April 30, 2010 12:23

Wow. Crashing every day and now only 'once in a while'. Crazy. Yes, Fluent 12 on Linux has embedded windows. I am not a fan of the embedded windows, and always unembed the graphics windows to view my geometry properly. This new Fluent 12 layout causes me much frustration. Additionally there is a focus problem with the main window, when I click on it with the mouse it does not come to the forefront, other windows, like contour or vector panels (any non-embedable panel) remain in front of it. Annoying to no end. I question the sincerely of the claim from Ansys that the monitor-induced-crashing is a problem unique to your systems (both of them). I need to install Fluent 12 on my own linux PC and see if the monitor problem occurs. Then we'd have a case for four systems with the same problem. Perhaps Ansys should consider selling well designed software as a strategy to sell more software.

chris21 May 24, 2010 20:11

I always have crashing issues when it comes to using monitors to check for convergence with Fluent 12 in Windows. This even occurs when using embedded windows, and I know that my workstation is powerful enough for any comparable job utilyzing other software. The case is not so complicated, so I'm having a hard time understanding how such widely used and expensive software could be so glitchy and in many ways broken. Granted, I'm extremely new to Fluent, so I admittedly have caused many errors in calculations before, but the more I learn about this software, the more I dislike it.

sumer May 25, 2010 01:06

I had this "problem" in Fluent 6.3 version. Fluent would just stop iterating after quite a few thousands iterations (time-dependent Euler). I don't recall the error message but Fluent Support suggested I disable plotting for the monitors. I did that and it "solved" the issue. I don't know about Fluent 12.0 or 12.1 though. Now I am checking the monitor files with Xgrace for time dependent runs.
I am running Fluent 12.1 64 bit on a cluster with Rocks+ (Red Hat 5).

chris21 May 25, 2010 01:19

Quote:

Originally Posted by sumer (Post 260052)
I had this "problem" in Fluent 6.3 version. Fluent would just stop iterating after quite a few thousands iterations (time-dependent Euler). I don't recall the error message but Fluent Support suggested I disable plotting for the monitors. I did that and it "solved" the issue. I don't know about Fluent 12.0 or 12.1 though. Now I am checking the monitor files with Xgrace for time dependent runs.
I am running Fluent 12.1 64 bit on a cluster with Rocks+ (Red Hat 5).

I'm pretty sure that disabling the monitor plots would fix the problem in Fluent 12 and 12.1 as well, it's just extremely inconvenient. It seems like it's just Fluent handling the graphical tasks poorly. It sounds like trying some alternative software is the way to go for these types of runs.


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